Roux-en-Y gastric bypass

Gastric bypass surgery also called Roux-en-Y gastric bypass, is a type of weight-loss surgery (bariatric surgery) where surgical staples are used to create small (∼30 to 60 mL) gastric pouch at the top of your stomach just distal to the gastroesophageal junction. The gastric pouch is then connected to your small intestine, bypassing (missing out) the rest of your stomach. The gastric pouch will hold about 1 cup of food. This means it takes less food to make you feel full and you’ll absorb fewer calories from the food you eat. Most of your stomach is disconnected so food won’t go to it, but the rest of your stomach will still be there. It delivers chemicals from the pancreas to help digest food that comes from the small pouch. The small pouch at the top of your stomach is the only part of your stomach that receives food. This greatly limits the amount that you can comfortably eat and drink at one time. Next, the small intestine is then cut a short distance below the main stomach and connected to the new pouch. Your surgeon will attach one end of it to the small stomach pouch and the other end lower down on the small intestine, making a “Y” shape. That’s the bypass part of the procedure. Doctors use the laparoscopic method for most gastric bypasses.

In summary, gastric bypass surgery or Roux-en-Y gastric bypass permits ingested food to pass directly from your esophagus through your small stomach pouch before proceeding directly into the jejunum, with little or no gastric or duodenal phase of digestion, because food never enters the body of the stomach or the duodenum. The main part of your stomach, however, continues to make digestive juices. The portion of the small intestine still attached to the main stomach is reattached farther down. This allows the digestive juices to flow to the small intestine. Because food now bypasses a portion of the small intestine, fewer nutrients and calories are absorbed.

Gastric bypass surgery is done when lifestyle intervention (diet and physical activity) and drugs haven’t worked or when you have serious health problems because of your weight.

Gastric bypass surgery or Roux-en-Y gastric bypass is the second most common type of weight loss surgery in the United States after the gastric sleeve surgery (sleeve gastrectomy) ¹, ². Gastric sleeve surgery (sleeve gastrectomy) and gastric bypass (Roux-en-Y gastric bypass) together are the most popular procedures (77%), whereas laparoscopic adjustable gastric banding (gastric banding) has become less popular due to poor long-term results ³.

1. The advantages of the gastric bypass surgery or Roux-en-Y gastric bypass procedure are ⁴, ⁵, ⁶:
   • it is reliable for long-lasting weight loss;
   • it is effective for remission of obesity-associated conditions;
   • it is a refined and standardized technique.
2. The disadvantages of the gastric bypass surgery or Roux-en-Y gastric bypass procedure are ⁴:
   • it is technically more complex when compared to sleeve gastrectomy or gastric band;
   • more vitamin and mineral deficiencies than sleeve gastrectomy or gastric banding;
   • there is a risk for small bowel complications and obstruction;
   • there is a risk of developing ulcers, especially with non-steroidal anti-inflammatory drugs (NSAIDs) or tobacco use;
   • may cause “dumping syndrome”, a feeling of sickness after eating or drinking, especially sweets.

Gastric bypass surgery can provide long-term weight loss. The amount of weight you lose depends on your type of surgery and your change in lifestyle habits. It may be possible to lose 60 percent, or even more, of your excess weight within two years.

In addition to weight loss, gastric bypass surgery may improve or resolve conditions often related to being overweight, including:

• Gastroesophageal reflux disease
• Heart disease
• High blood pressure
• High cholesterol
• Obstructive sleep apnea
• Type 2 diabetes
• Stroke
• Infertility

Gastric bypass surgery can also improve your ability to perform routine daily activities, which could help improve your quality of life.

Figure 1. Gastric bypass before and after

Footnote: Before gastric bypass, food (see arrows) enters your stomach and passes into the small intestine. After surgery, the amount of food you can eat is reduced due to the smaller stomach pouch. Food is also redirected so that it bypasses most of your stomach and the first section of your small intestine (duodenum). Food flows directly into the middle section of your small intestine (jejunum), altering the secretion of gastrointestinal hormones and thereby affecting your appetite and metabolism.

Figure 2. Gastric bypass surgery or Roux-en-Y gastric bypass

Gastric sleeve vs Gastric bypass surgery

Gastric sleeve surgery, also called “vertical sleeve gastrectomy” (VSG) or “sleeve gastrectomy“, is a newer type of weight loss surgery (bariatric surgery) where a surgeon removes most of your stomach (removing approximately 80% of the stomach) and makes a narrow tube or “sleeve” out of the remaining stomach, leaving only a banana-shaped section that is closed with staples. Your new, banana-shaped stomach is much smaller than your original stomach. After the gastric sleeve surgery, your stomach will hold only about a tenth of what it did before, making you feel full sooner after eating a small amount of food and be less hungry. You might also feel less hungry because your smaller stomach will produce lower levels of a hormone called ghrelin, which causes hunger and you may lose from 50 to 90 pounds. Taking out part of your stomach may also affect other hormones and bacteria in your gastrointestinal system that affect appetite and metabolism. Gastric sleeve surgery cannot be reversed because some of your stomach is permanently removed. Endoscopic gastric sleeve surgery is less invasive and cheaper than other forms of bariatric surgery.

In contrast, a gastric bypass surgery also called Roux-en-Y gastric bypass is a type of weight-loss surgery (bariatric surgery) where surgical staples are used to create a small pouch at the top of your stomach (Figure 2). This pouch will hold about 1 cup of food. The pouch is then connected to your small intestine, bypassing (missing out) the rest of the stomach. This means it takes less food to make you feel full and you’ll absorb fewer calories from the food you eat because the food you eat will bypass most of your stomach and the upper part of your small intestine. Gastric bypass surgery is one of the most common types of bariatric surgery in the United States. Gastric bypass surgery is done when diet and exercise haven’t worked or when you have serious health problems because of your weight.

Unlike gastric sleeve, in gastric bypass surgery or Roux-en-Y gastric bypass surgery, the rest of your stomach will still be there, but food won’t go to it. The small pouch at the top of your stomach is the only part of your stomach that receives food. This greatly limits the amount that you can comfortably eat and drink at one time.

Next, your small intestine is then cut a short distance below the main stomach and connected to the new pouch. Your surgeon will attach one end of your small intestine to the small stomach pouch and the other end lower down on the small intestine, making a “Y” shape. That’s the bypass part of the procedure. This allows digestive juices in your stomach to flow from the bypassed part of the small intestine to the lower part of the small intestine, so that food can be fully digested. The main part of the stomach, however, continues to make digestive juices. The portion of the small intestine still attached to the main stomach is reattached farther down. This allows the digestive juices to flow to the small intestine. Because food now bypasses the first portion of your small intestine called the duodenum, fewer nutrients and calories are absorbed.

The gastric bypass surgery also changes hormones, bacteria, and other substances in the gastrointestinal tract that may affect appetite and metabolism. The rest of your stomach is still there. It delivers chemicals from the pancreas to help digest food that comes from the small pouch. Doctors use the laparoscopic method for most gastric bypasses.

Gastric bypass is difficult to reverse, although a surgeon may do it if medically necessary.

Gastric bypass surgery can provide long-term weight loss. The amount of weight you lose depends on your type of surgery and your change in lifestyle habits. It may be possible to lose 60 percent, or even more, of your excess weight within two years.

Most people lose weight for 1 to 2 years after gastric bypass or gastric sleeve surgery, then they stop losing weight. However, neither gastric bypass surgery nor gastric sleeve surgery is a miracle procedure — and it isn’t for everyone. Having gastric bypass or other weight-loss surgery doesn’t guarantee that you’ll lose all your excess weight or that you’ll keep it off over the long term. Nor is it a way to avoid making changes in your diet and exercise habits. In fact, you can regain the weight you lose with gastric bypass surgery if you don’t stick with the lifestyle changes. But if you think gastric bypass surgery or gastric sleeve surgery might be right for you, talk with your doctor ⁷.

Many factors will determine which type of surgery is the best type for you, including how much weight you need to lose and any illnesses you might have.

Your doctor will do a detailed assessment and discuss with you the best option, including the risks.

Iron deficiency and anemia are more common after a gastric bypass than after a sleeve gastrectomy or an adjustable gastric band. This is especially true in women. In fact, iron deficiency can occur in more than half of women who are past menopause when they have gastric bypass surgery.

Figure 3. Gastric sleeve vs Gastric bypass

What is mini gastric bypass?

Mini-gastric bypass also called single-anastomosis gastric bypass, is a modification of the gastric bypass surgery that has only one connection (single-anastomosis) which differs from the traditional Roux-en-Y gastric bypass which requires two connections (two anastomoses), making it easier to perform, has a shorter learning curve, easy revise or reverse and is associated with fewer major complications ⁸, ⁹, ¹⁰, ¹¹, ¹². Most patients stay one to two nights in the hospital following mini-gastric bypass surgery, and usually will need 10-14 days off work.

Mini-gastric bypass was first performed by Dr. Rutledge in 1997 ¹³. Mini-gastric bypass constructs a lesser curvature gastric conduit to or below the “crow’s foot” and a connection (single-anastomosis) to an anti-colic loop of jejunum 150–200 cm distal to the trietz ligament ⁹.

Mini-gastric bypass has important technical details like the gastric pouch size, gastro-jejunostomy size and bypass length ⁹. When these individual components of the operation are used in different ways, these give different results ¹⁴. There are reports of mini-gastric bypass being used from 150 cm to up to more than 300 cm. Mini-gastric bypass gives different results as per the length of the bypass ¹⁴. In addition to this, different surgeons are performing gastrojejunostomy in different ways with different staples varying from 30 mm to 60 mm staple sizes and hand sewn instead of total stapled anastomosis ⁹.

It is now widely acknowledged that mini-gastric bypass is at least as effective as Roux-en-Y gastric bypass, if not more effective, when it comes to weight loss and comorbidity resolution ⁸, ¹⁵. In their comparative analysis of Roux-en-Y gastric bypass and mini-gastric bypass over a 10-year period, Lee et al. ⁸ found that at 5 years, mini-gastric bypass had a significantly lower body mass index (BMI) (27.7 vs 29.2) and higher excess weight loss (72.9% vs 60.1%); there was no significant difference in the improvement of comorbidities. A randomized study from the same group ¹⁵ showed a lower complication rate with mini-gastric bypass (7.5% vs 20%) and a higher proportion of patients achieving an excess weight loss >50% (95% vs 75%).

Numerous articles over the past 15 years have demonstrated that the original mini-gastric bypass technique leads to excellent results, and in the vast majority of patients avoids complications and problems such as bile reflux gastritis, and excessive or inadequate weight loss ⁹. Additionally, mini-gastric bypass produces hormonal changes and also affects patient’s bile acid pool ¹⁶. Furthermore, general surgery and bariatric studies show that operations which includes both a gastric and an intestinal component out performs purely gastric restrictive procedures, like the gastric band and sleeve gastrectomy ¹⁷, ¹⁸, ¹⁹, ²⁰.

However, despite of the popularity of mini-gastric bypass, it is still limited by some concerns such as gastric and esophageal bile reflux, marginal ulcer, poor follow-up, and remnant gastric cancer ²¹. Previous large sample size and observational studies have reported the overall rate complications of 2% to 7.9% ²², ²³, ²⁴, ulcer rate of 0.2% to 4% ²², ²³, ²⁴, ²⁵, ²⁶, stenosis rate of 0.1% to 0.8% ²⁷, ²³, ²⁴, vomiting rate of 6% ²⁷, anemia rate of 1.5% to 4.9% ²², ²⁷, ²⁵, bile reflux rate of 0% to 1.6% ²², ²⁷, ²⁵, ²⁴, GERD rate of 2% ²⁷ and malnutrition rate of 2% ²⁷ for patients receiving mini-gastric bypass. Ulcer and stenosis generally happened at anastomosis area, which may account for the higher ulcer rate in mini-gastric bypass patients ²⁰. After tens of thousands of mini-gastric bypasss performed since 1997, there has been only one gastric cancer reported in a mini-gastric bypass patient and it was in the bypassed stomach and not in the pouch ²⁸.

Despite many thousands of published cases, mini-gastric bypass continues to be controversial and many national societies do not regard it as a mainstream weight loss procedure ²⁹. Though most institutes completely ignore this operation, in India mini-gastric bypass is the 2nd commonest weight loss procedure following the gastric sleeve surgery, outpacing the standard Roux-en-Y gastric bypass ³⁰.

Figure 4. Mini-gastric bypass

Where to find a weight loss surgeon near me?

To find a board certified weight loss surgeon (the American Society for Metabolic and Bariatric Surgery) please go here https://asmbs.org/patients/find-a-provider

Why is gastric bypass surgery done?

Gastric bypass surgery is done to help you lose excess weight and reduce your risk of potentially life-threatening weight-related health problems, including:

• Gastroesophageal reflux disease (GERD)
• Heart disease
• High blood pressure
• High cholesterol
• Obstructive sleep apnea
• Type 2 diabetes
• Stroke
• Infertility

Gastric bypass surgery is typically done only after you’ve tried to lose weight by improving your diet and exercise habits.

Gastric bypass alternative

The alternatives to gastric bypass surgery are lifestyle changes such as diet and exercise, or lifestyle changes combined with weight-loss medications or lap band surgery (adjustable gastric banding) or gastric sleeve surgery. You can get professional help with this: ask your doctor. A prospective, cross-sectional study ³¹ assessed weight loss, food tolerance and diet quality in 130 subjects (14 obese pre-surgical controls, 13 adjustable gastric banding, 62 gastric sleeve and 41 Roux-en-Y gastric bypass) found the obese pre-surgical controls and adjustable gastric banding groups consumed significantly more high-calorie extra foods, resulting in poor weight loss and food tolerance outcomes for the adjustable gastric banding group. The control and adjustable gastric banding groups consumed significantly more high-calorie extra foods (9.2 and 7.7 daily serves respectively) compared with the gastric sleeve (3.4 serves) and Roux-en-Y gastric bypass (4.0 serves) groups. There were several significant correlations between food tolerance and dietary intake including breads and cereals and meat and meat alternatives.

Laparoscopic adjustable gastric banding or Lap Band

In laparoscopic adjustable gastric banding, a hollow, flexible silicone band is placed around the upper stomach, which causes a restrictive effect, reduces stomach capacity, and produces rapid feelings of satiety. The band is tightened by injecting saline into it through a subcutaneous port, which is located just inferior to the sternum or lateral to the umbilicus (Figure 5). Because of a higher complication rate and less weight loss compared with the other two most common procedures (gastric sleeve and Roux-en-Y gastric bypass), the demand for gastric banding is decreasing in the United States ³².

Figure 5. Adjustable Gastric Banding

Who is gastric bypass surgery for?

Gastric bypass and other weight-loss surgeries are major, life-changing procedures. While weight-loss surgery can help reduce your risk of weight-related health problems — such as type 2 diabetes, high blood pressure, heart disease and obstructive sleep apnea — it can also pose major risks and complications. You may need to meet certain medical guidelines to qualify for weight-loss surgery. You likely will have an extensive screening process to see if you qualify.

In general, gastric bypass and other weight-loss surgeries could be an option for you if:

• Your efforts to lose weight with diet and exercise have been unsuccessful
• Your body mass index (BMI) is 40 kg/m² or higher (extreme obesity).
• Your BMI is 35 to 39.9 kg/m² (obesity), and you have a serious weight-related health problem, such as type 2 diabetes, high blood pressure or severe sleep apnea.
• In some cases, you may qualify for certain types of weight-loss surgery if your BMI is 30 to 34 kg/m² and you have serious weight-related health problems.
• You’re a teenager who’s gone through puberty, your BMI is 35 kg/m² or more, and you have serious obesity-related health problems, such as type 2 diabetes or severe sleep apnea

Even if you meet these general guidelines, you still may need to meet certain other medical guidelines to qualify for weight-loss surgery. You likely will have an extensive screening process to see if you qualify.

A team of health professionals — usually including a doctor, dietitian, psychologist and surgeon — evaluate whether gastric bypass or one of the other forms of weight-loss surgery is appropriate for you. This evaluation generally determines if the health benefits of the surgery outweigh the potentially serious risks, and if you’re medically ready to undergo the procedure.

The evaluation also determines if you’re psychologically ready to undergo weight-loss surgery. The procedure may increase certain risks in people with existing mental health conditions that aren’t effectively managed.

For example, recent studies have identified an increased risk of suicide in people who have had weight-loss surgery. This risk is greatest in those who have attempted suicide in the past. More research is needed to understand whether changes related to the surgery itself play a role in increasing suicide risk.

A history of suicidal thoughts or attempts does not necessarily mean bariatric surgery isn’t right for you, but your health care team should carefully evaluate your history and plan for close monitoring and support before and after the surgery.

When conducting an evaluation for gastric bypass surgery, the health care team considers:

• Your nutrition and weight history. The team reviews your weight trends, diet attempts, eating habits, exercise regimen, stress level, time constraints, motivation and other factors.
• Your medical condition. Some health problems increase the risks associated with having surgery or may be worsened by surgery, such as blood clots, liver disease, heart problems, kidney stones and nutritional deficiencies. The team evaluates what medications you take, how much alcohol you drink and whether you smoke. You will be evaluated for sleep apnea and receive a thorough physical exam and laboratory testing. The results of these tests and exams may help determine eligibility for weight-loss surgery.
• Your psychological status. Certain mental health conditions may contribute to obesity or make it more difficult for you to maintain the health benefits of gastric bypass surgery. These may include binge-eating disorder, substance abuse, anxiety disorders, major depression, schizophrenia, severe bipolar disorder and issues related to childhood sexual abuse. While these conditions may not prevent you from having gastric bypass surgery, your doctors may want to postpone surgery to ensure that any condition or significant sources of stress are appropriately treated and managed.
• Your motivation. The team will also assess your willingness and ability to follow through with recommendations made by your health care team and to carry out prescribed changes in your diet and exercise routine.
• Your age. There’s no specific age limit for gastric bypass surgery, but, until recently, the procedure was considered too risky for teenagers and older adults. Newer studies have found gastric bypass surgery can be safe and effective for adults ages 60 and older. The procedure is also now considered an option for some teenagers with a BMI of 35 or more and serious obesity-related health problems.

You must also be willing to make permanent changes to lead a healthier lifestyle. You may be required to participate in long-term follow-up plans that include monitoring your nutrition, your lifestyle and behavior, and your medical conditions.

Check with your health insurance plan or your regional Medicare or Medicaid office to find out if your policy covers weight-loss surgery. If you plan to rely on health insurance coverage for your gastric bypass surgery, you will need to get preapproval from your health insurance company. The preapproval process typically requires documentation from your team of doctors that justifies your medical need for gastric bypass surgery.

Different health insurers have different requirements to prove your medical need for gastric bypass surgery. Your health insurer may not cover gastric bypass surgery at all or may cover only parts of the process. To avoid unpleasant financial surprises, it’s a good idea to check to see what specific services are covered before starting the evaluation process. You may have to pay for some portion of the costs yourself.

When weight-loss surgery doesn’t work

It’s possible to not lose enough weight or to regain weight after weight-loss surgery. This weight gain can happen if you don’t follow the recommended lifestyle changes. If you frequently snack on high-calorie foods, for instance, you may have inadequate weight loss. To help avoid regaining weight, you must make permanent healthy changes in your diet and get regular physical activity and exercise.

It’s important to keep all of your scheduled follow-up appointments after weight-loss surgery so that your doctor can monitor your progress. If you notice that you aren’t losing weight or you develop complications after your surgery, see your doctor immediately.

What happens if you gain back weight after gastric bypass surgery?

If you begin to regain weight after gastric bypass surgery, talk to your doctor. You may have a sense of what’s causing your weight gain. However, you may need a more thorough evaluation to determine what factors — medical, psychological, lifestyle — are involved in the weight gain.

You may have gained weight after gastric bypass surgery because of changes in your stomach and intestine that allow you to eat more and absorb more calories.

It’s also possible that your diet and exercise habits have slipped, in which case you must typically lose the regained weight the old-fashioned way — both by reducing your calorie intake and increasing your physical activity.

In some cases, a second surgery to repair — or redo — a gastric bypass may be appropriate. This is especially true if the anatomy of your stomach and small intestine have changed, such as with a fistula (additional connection between the stomach and intestine).

However, a second surgery has an increased risk of complications, including infection, bleeding and leaks in the gastrointestinal tract. Because of these risks, gastric bypass surgery usually isn’t redone if you regain weight because of poor diet or exercise habits.

Gastric bypass surgery can be an effective treatment for obesity, and most people do lose weight after the procedure if they are adequately prepared for the changes that are necessary. But you’ll always be at risk of regaining weight, even years later.

To help reach your weight-loss goal and prevent weight regain, it’s crucial to make lifestyle changes along with having gastric bypass surgery.

Gastric bypass surgery risks

As with any major surgery, gastric bypass and other weight-loss surgeries pose potential health risks, both in the short term and long term.

Risks associated with the surgical procedure are similar to any abdominal surgery and can include:

• Excessive bleeding
• Infection
• Adverse reactions to anesthesia
• Blood clots
• Lung or breathing problems
• Leaks in your gastrointestinal system

Longer term risks and complications of gastric bypass surgery can include:

• Bowel obstruction
• Dumping syndrome, causing diarrhea, nausea or vomiting
• Gallstones
• Hernias
• Low blood sugar (hypoglycemia)
• Malnutrition
• Stomach perforation
• Ulcers
• Vomiting
• Anastomotic leaking

Rarely, complications of gastric bypass can be fatal.

Risks of anastomotic leaking

Anastomotic leaks happen in 1.5% to 6% of gastric bypass procedures, depending on the type of surgery. A leak may happen up to several weeks later. Most develop within 3 days after surgery.

A leaking anastomosis may cause bleeding and infection until it is treated. These leaks are serious and can be life-threatening. Long-term complications may include ulcers, scarring, and narrowing of the anastomosis (where the intestine is connected to the gastric pouch), known as a stricture. A drainage tract through the skin called a fistula may also develop. A fistula could develop between the gastric pouch and the bypassed stomach. Pneumonia is another dangerous complication, because digestive juices can spill into the lungs.

If you are considering gastric bypass surgery for obesity, discuss the procedure carefully with your healthcare provider. The overall risk of serious complications should be weighed against the risk of continued obesity. Remember that gastric bypass surgery works best when combined with long-term, healthy lifestyle choices. These involve good nutritional eating habits and regular exercise.

Symptoms of an anastomotic leak include:

• Rapid heart rate
• Fever
• Stomach pain
• Drainage from a surgical wound
• Nausea and vomiting
• Pain in the left shoulder area
• Low blood pressure
• Decreased urine output

The more obese you are, the more at risk you are for an anastomotic leak. Other risk factors include being male, having other medical problems besides obesity, and having a history of previous abdominal surgery.

Diagnosis and treatment of anastomotic leaking

A diagnostic test used to look for anastomotic leaking is an upper GI or a CT scan. Both involve swallowing some liquid contrast dye and then taking X-rays to see if the dye is leaking through the anastomosis. Even if you have a negative exam but still have symptoms, your healthcare provider may recommend an emergency operation to look for a leak.

The medical team treating an anastomotic leak will likely take these steps:

• Give you antibiotics through an intravenous line (IV).
• Drain any infection caused by the leak, repair the leak, or make a new anastomosis by operating again.
• Use an upper endoscopy to place a temporary stent across the leaking area, from the inside of the gastric pouch or the small intestine.
• Stop all oral feedings. You may be fed through a tube that goes directly into your intestine until the leak has healed.

How you prepare for gastric bypass surgery

If you qualify for gastric bypass surgery, your health care team gives you instructions on how to prepare for surgery. You may need to have various lab tests and exams before surgery.

Food and medications

Before your gastric bypass surgery, give your doctor and any other health care providers a list of all medicines, vitamins, minerals, and herbal or dietary supplements you take. You may have restrictions on eating and drinking and which medications you can take.

If you take blood-thinning medications, talk with your doctor before your surgery. Because these medications affect clotting and bleeding, your blood-thinning medication routine may need to be changed.

If you have diabetes, talk with the doctor who manages your insulin or other diabetes medications for specific instructions on taking or adjusting them after surgery.

Other precautions

You will be required to start a physical activity program and to stop any tobacco use.

You may also need to prepare by planning ahead for your recovery after surgery. For instance, arrange for help at home if you think you’ll need it.

Gastric bypass surgery is done in the hospital. Depending on your recovery, your hospital stay may last around three to five days.

Gastric bypass procedure

Before you go to the operating room, you’ll change into a gown and be asked several questions by both doctors and nurses. In the operating room, you are given a general anesthetic before your surgery begins. The anesthetic is medicine that keeps you asleep and comfortable during surgery.

During the gastric bypass surgery

The specifics of your gastric bypass surgery depend on your individual situation and the doctor’s practices. Some surgeries are done with traditional large (open) incisions in your abdomen. However, most are performed laparoscopically, which involves inserting instruments through multiple small incisions in the abdomen.

After making the incisions with the open or laparoscopic technique, the surgeon cuts across the top of your stomach, sealing it off from the rest of your stomach. The resulting pouch is about the size of a walnut and can hold only about an ounce of food. Normally, your stomach can hold about 3 pints of food.

Then, the surgeon cuts the small intestine and sews part of it directly onto the pouch. Food then goes into this small pouch of stomach and then directly into the small intestine sewn to it. Food bypasses most of your stomach and the first section of your small intestine, and instead enters directly into the middle part of your small intestine.

Surgery usually takes a few hours. After surgery, you awaken in a recovery room, where medical staff monitors you for any complications.

After the gastric bypass surgery

Immediately after gastric bypass surgery, you may have liquids but no solid food as your stomach and intestines begin to heal. You’ll then follow a special diet plan that changes slowly from liquids to pureed foods. After that, you can eat soft foods, then move on to firmer foods as your body is able to tolerate them.

You may have many restrictions or limits on how much and what you can eat and drink. Your doctor will recommend you take vitamin and mineral supplements after surgery, including a multivitamin with iron, calcium and vitamin B-12.

You’ll also have frequent medical checkups to monitor your health in the first several months after weight-loss surgery. You may need laboratory testing, blood work and various exams.

You may experience changes as your body reacts to the rapid weight loss in the first three to six months after gastric bypass, including:

• Body aches
• Feeling tired, as if you have the flu
• Feeling cold
• Dry skin
• Hair thinning and hair loss
• Mood changes

Gastric bypass diet

A gastric bypass diet is for people who are recovering from gastric bypass surgery to help them heal and change their eating habits.

Diet recommendations after gastric bypass surgery vary depending on where the surgery is performed and your individual situation.

Your doctor or a registered dietitian will talk with you about the diet you’ll need to follow after surgery, explaining what types of food and how much you can eat at each meal. Closely following your gastric bypass diet can help you lose weight safely.

A gastric bypass diet typically follows a staged approach to help you ease back into eating solid foods as you recover. How quickly you move from one step to the next depends on how fast your body heals and adjusts to the change in eating patterns. You can usually start eating regular foods about three months after surgery.

After gastric bypass surgery, you must be careful to drink enough fluids to avoid dehydration, and to pay extra attention to signs that you feel hungry or full.

Liquids

For the first day or so after surgery, you’ll only be allowed to drink clear liquids. Sip slowly and drink only 2 to 3 ounces (59 to 89 milliliters) at a time. Once you’re handling clear liquids, you can start having other liquids, such as skim or low-fat milk.

Liquids you can have during stage 1:

• Broth
• Unsweetened juice
• Decaffeinated tea or coffee
• Milk (skim or 1 percent)
• Strained cream soup
• Sugar-free gelatin or popsicles

Pureed foods

Once you’re able to tolerate liquids for a few days, you can begin to eat strained and pureed (mashed up) foods. During this phase, you can only eat foods that have the consistency of a smooth paste or a thick liquid, without any solid pieces of food in the mixture.

To puree your foods, choose foods that will blend well, such as:

• Lean ground meats
• Beans
• Fish
• Eggs
• Soft fruits and cooked vegetables
• Cottage cheese

Blend solid foods with a liquid, such as:

• Water
• Skim milk
• Juice with no sugar added
• Broth

It’s important that you don’t eat and drink at the same time. Wait about 30 minutes after a meal to drink anything. Also keep in mind that your digestive system might still be sensitive to spicy foods or dairy products. If you’d like to eat these foods during this phase, add them into your diet slowly and in small amounts.

Soft foods

After a few weeks of pureed foods, and with your doctor’s okay, you can add soft foods — in the form of small, tender, easily chewed pieces — to your diet.

During this stage, your diet can include:

• Ground or finely diced meats
• Canned or soft fresh fruit (without seeds or skin)
• Cooked vegetables (without skin)

Solid foods

After about eight weeks on the gastric bypass diet, you can gradually return to eating firmer foods. But foods must still be chopped or diced. Start slowly with regular foods to see what foods you can tolerate. You may find that you still have difficulty eating spicier foods or foods with crunchy textures.

Even at this stage, there are foods you should avoid because they may cause gastrointestinal symptoms, such as nausea, pain or vomiting.

Foods to avoid:

• Nuts and seeds
• Popcorn
• Dried fruits
• Carbonated beverages
• Granola
• Stringy or fibrous vegetables, such as celery, broccoli, corn or cabbage
• Tough meats or meats with gristle
• Fried foods
• Breads

Over time, you may be able to try some of these foods again, with the guidance of your doctor.

A new healthy diet

Three to four months after weight-loss surgery, you may be able to start eating a normal healthy diet, depending on your situation and any foods you may not be able to tolerate. It’s possible that foods that initially irritated your stomach after surgery may become more tolerable as your stomach continues to heal.

Throughout the diet

To ensure that you get enough vitamins and minerals and keep your weight-loss goals on track, at each stage of the gastric bypass diet, you should:

• Eat and drink slowly. Eating or drinking too quickly may cause dumping syndrome — when foods and liquids enter your small intestine rapidly and in larger amounts than normal, causing nausea, vomiting, dizziness, sweating and eventually diarrhea. To prevent dumping syndrome, choose foods and liquids low in fat and sugar, eat and drink slowly, and wait 30 to 45 minutes before or after each meal to drink liquids. Take at least 30 minutes to eat your meals and 30 to 60 minutes to drink 1 cup (237 milliliters) of liquid.
• Keep meals small. During the diet progression, you should eat several small meals a day and sip liquids slowly throughout the day (not with meals). You might first start with six small meals a day, then move to four meals and finally, when following a regular diet, decrease to three meals a day. Each meal should include about a half-cup to a cup of food. Make sure you eat only the recommended amounts and stop eating before you feel full
• Drink liquids between meals. Expect to drink at least 6 to 8 cups (48 to 64 ounces, or 1.4 to 1.9 liters) of fluids a day to prevent dehydration. Drinking liquids with your meals can cause pain, nausea and vomiting as well as dumping syndrome. Also, drinking too much liquid at or around mealtime can leave you feeling overly full and prevent you from eating enough nutrient-rich food.
• Chew food thoroughly. The new opening that leads from your stomach into your intestine is very small, and larger pieces of food can block the opening. Blockages prevent food from leaving your stomach and can cause vomiting, nausea and abdominal pain. Take small bites of food and chew them to a pureed consistency before swallowing. If you can’t chew the food thoroughly, don’t swallow it.
• Focus on high-protein foods. Immediately after your surgery, eating high-protein foods can help you heal. High-protein, low-fat choices remain a good long-term diet option after your surgery, as well. Try adding lean cuts of beef, chicken, pork, fish or beans to your diet. Low-fat cheese, cottage cheese and yogurts also are good protein sources.
• Avoid foods that are high in fat and sugar. After your surgery, it may be difficult for your digestive system to tolerate foods that are high in fat or added sugars. Avoid foods that are high in fat (such as fried foods, ice cream and candy bars). Look for sugar-free options of soft drinks and dairy products.
• Try new foods one at a time. After surgery, certain foods may cause nausea, pain and vomiting or may block the opening of the stomach. The ability to tolerate foods varies from person to person. Try one new food at a time and chew thoroughly before swallowing. If a food causes discomfort, don’t eat it. As time passes, you may be able to eat this food. Foods and liquids that commonly cause discomfort include meat, bread, raw vegetables, fried foods and carbonated beverages.
• Take recommended vitamin and mineral supplements. Because a portion of your small intestine is bypassed after surgery, your body won’t be able to absorb enough nutrients from your food. You’ll likely need to take a multivitamin supplement every day for the rest of your life. Talk to your doctor about what type of multivitamin might be right for you and whether you might need to take additional supplements, such as calcium.

The greatest risks of the gastric bypass diet come from not following the diet properly. If you eat too much or eat food that you shouldn’t, you could have complications. These include:

• Dumping syndrome. This complication occurs most often after eating foods high in sugar or fat. These foods travel quickly through your stomach pouch and “dump” into your intestine. Dumping syndrome can cause nausea, vomiting, dizziness, sweating and eventually diarrhea.
• Dehydration. Because you’re not supposed to drink fluids with your meals, some people become dehydrated. You can prevent dehydration by sipping 48 to 64 ounces (1.4 to 1.9 liters) of water and other low-calorie beverages throughout the day.
• Nausea and vomiting. If you eat too much, eat too fast or don’t chew your food adequately, you may become nauseated or vomit after meals.
• Constipation. If you don’t follow a regular schedule for eating your meals, don’t eat enough fiber or don’t exercise, you may become constipated.
• Blocked opening of your stomach pouch. It’s possible for food to become lodged at the opening of your stomach pouch, even if you carefully follow the diet. Signs and symptoms of a blocked stomach opening include ongoing nausea, vomiting and abdominal pain. Call your doctor if you have these symptoms for more than two days.
• Weight gain or failure to lose weight. If you continue to gain weight or fail to lose weight on the gastric bypass diet, it’s possible you could be eating too many calories. Talk to your doctor or dietitian about changes you can make to your diet.

Dumping syndrome after gastric bypass surgery

Dumping syndrome after gastric bypass surgery is when food gets “dumped” directly from your stomach pouch into your small intestine without being digested. There are 2 types of dumping syndrome: early and late. Early dumping happens 10 to 30 minutes after a meal. Late dumping happens 1 to 3 hours after eating. Each has slightly different symptoms, such as abdominal cramping, fast heartbeat, lightheadedness, and diarrhea.

What causes dumping syndrome after gastric bypass surgery?

Early dumping syndrome can occur because of the dense mass of food that gets dumped into your small intestine at an earlier stage of digestion. The intestines sense that this food mass is too concentrated, and release gut hormones. Your body reacts by shifting fluid circulating in your bloodstream to the inside of your intestine. As a result, your intestines become fuller and bloated. Diarrhea often occurs 30 to 60 minutes later. In addition, certain substances are released by your intestine that affect heart rate and often blood pressure, causing many of the symptoms of early dumping. This can lead to lightheadedness or even fainting.

Symptoms of late dumping happen because of a decrease in blood sugar level (reactive hypoglycemia). Reactive hypoglycemia is low blood sugar caused 1 to 3 hours after a large surge of insulin. You are more likely to have dumping syndrome if you eat a meal heavy in starches or sugars. The sugars can be either fructose or table sugar (sucrose). Insulin levels can increase to high levels, then lower your blood sugar too much.

Who is at risk for dumping syndrome after gastric bypass surgery?

Dumping syndrome can happen in at least 3 out of 20 people who have had a part of their stomach removed for any reason.

What are the symptoms of dumping syndrome after gastric bypass surgery?

Most people have early dumping symptoms. Typical early dumping symptoms can include:

• Bloating
• Sweating
• Abdominal cramps and pain
• Nausea
• Facial flushing
• Stomach growling or rumbling
• An urge to lie down after the meal
• Heart palpitations and fast heartbeat
• Dizziness or fainting
• Diarrhea

About 1 in 4 people have late dumping symptoms. The symptoms of late dumping syndrome can include:

• Heart palpitations
• Sweating
• Hunger
• Confusion
• Fatigue
• Aggression
• Tremors
• Fainting

How is dumping syndrome after gastric bypass surgery diagnosed?

Your healthcare team will likely diagnose dumping syndrome based on your symptoms and when they occur. Tell him or her which foods or liquids give you symptoms. You may also need to have a glucose tolerance test or hydrogen breath test to help your healthcare provider diagnose you.

How is dumping syndrome after gastric bypass surgery treated?

The main treatment for dumping syndrome is changes in your diet. These include

• Don’t drink liquids until at least 30 minutes after a meal.
• Divide your daily calories into 6 small meals.
• Lie down for 30 minutes after a meal to help control the symptoms.
• Choose complex carbohydrates such as whole grains.
• Avoid foods high in simple carbohydrates, such as those made white flour or sugar.
• Add more protein and fat to your meals.
• Stop eating dairy foods, if they cause problems.

Another option is to slow gastric emptying by making your food thicker. Your healthcare provider may advise adding 15 grams of guar gum or pectin to each meal. But many people don’t tolerate these additions to their food.

If dietary changes don’t help, your healthcare provider may give you some slow-release prescription medicines. In rare cases, these may help, but they often don’t work. In severe cases of dumping syndrome, your healthcare provider may suggest tube feeding or corrective surgery.

Iron deficiency after gastric bypass surgery

Iron deficiency is a side effect that results from the changes made during the surgery. Most of the iron from foods such as meats, legumes, and iron-fortified grains is absorbed in the first part of your small intestine (duodenum). But after a gastric bypass procedure, food bypasses the duodenum. This can lead to iron deficiency and other nutrition problems.

The amount of iron in a standard multivitamin (18 mg) may not be enough to prevent anemia if you have this kind of surgery. You will need to take more iron if you are iron deficient after a gastric bypass.

Who is at risk for iron deficiency after gastric bypass surgery?

Iron deficiency is more common in women who have this surgery after menopause. It can occur in more than half of women in this age group. Men who have had gastric bypass also may develop iron deficiency. But this side effect happens much less often in men.

What are the symptoms of iron deficiency after gastric bypass surgery?

Iron has many important roles in your body. It’s important for the health of your hair, skin, and nails. It also helps make hemoglobin. This is the substance inside red blood cells that carries oxygen throughout your body. When you are anemic because of iron deficiency, you may have:

• Lack of energy
• Weakness
• Headache
• Rapid heartbeat
• Hair loss
• Brittle nails
• Pale or yellow skin
• Shortness of breath
• Chest pain
• Strange pounding sensation in your ears
• Craving for ice or clay (pagophagia)

How is iron deficiency after gastric bypass surgery diagnosed?

Your healthcare provider will note any of the above symptoms. He or she will also order blood tests to find out if you have iron deficiency or anemia. In its early stages, iron deficiency begins to use up the stores of iron in your body. This can be seen by testing your levels of ferritin. Ferritin is a protein that stores iron in your body. If your ferritin levels are low, your iron is likely low.

If your iron deficiency has turned into iron deficiency anemia, you will need a complete blood count test to find any other problems. These might include low hemoglobin, lower numbers of red blood cells, and smaller red blood cell size.

For men, or for women past menopause, iron deficiency anemia might not be related to the gastric bypass surgery. Your healthcare provider will need to be certain that you are not anemic from blood loss elsewhere, such as from your intestine. You may need a colonoscopy to look for a source of blood loss from your large intestine.

How is iron deficiency after gastric bypass surgery treated?

Many people can raise their iron levels by making some changes to their diet. If your iron deficiency is related to a gastric bypass procedure, your healthcare team probably will prescribe iron supplements. This extra iron should come from a prescription from your provider, not from an over-the-counter (OTC) supplement you pick yourself. The exception to this is if your healthcare provider recommends a certain over-the-counter iron product for you. Your provider may recommend a certain type of iron that you could absorb better after a gastric bypass.

If you are a teen boy or girl, or a woman of childbearing age, you may need 2 multivitamins plus 50 mg to 100 mg of iron each day. You may also need a vitamin C supplement or other supplements to help your body absorb more iron. Your healthcare provider will tell you the right amount of iron that you need.

Iron supplement can cause side effects. Many people have constipation and nausea.

For some people, supplements aren’t enough. This is usually true for women with heavy menstrual periods. You may need iron through an IV (intravenous) line or blood transfusion. Or you may need more surgery on your bypass to increase the amount of iron you absorb.

Can iron deficiency after gastric bypass surgery be prevented?

You should have a blood tests before weight-loss surgery to find out if you have any vitamin or mineral deficiencies. These might be low levels of iron, vitamin B-12, or folate. Getting treatment for these deficiencies before your surgery will help your quality of life after surgery.

After gastric bypass surgery, you will need to monitor your level of iron and other nutrients for the rest of your life. You can develop iron deficiency and anemia years or decades after your gastric bypass surgery. Your healthcare provider should measure your iron levels 6 months after weight-loss surgery and at least once a year after that. You should also have a complete blood count test.

Red meat, poultry, seafood, leafy greens, legumes, iron-fortified grains, and other iron-fortified foods are all good sources of iron. Drinking more than 2 to 3 cups of milk a day may decrease how much iron you absorb. But dietary changes alone may not be enough to prevent or fix an iron deficiency related to a gastric bypass procedure. Work with your healthcare provider to find the right iron supplement plan for you.

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