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Bariatric Dumping Syndrome: What You Need To Know

Bariatric Dumping Syndrome: What You Need To Know

Dumping syndrome, or rapid gastric emptying, is a condition that can develop following bariatric surgery. Although it is a condition that affects many people after undergoing bariatric surgery, dumping after bariatric surgery can be preventable and treatable.

What Causes Bariatric Dumping?

Dumping syndrome after bariatric surgery is a common condition that develops because of surgical changes to the digestive tract. Many bariatric surgeries aim to decrease the stomach size to limit nutrient digestion and absorption for weight loss. The decreased stomach size causes food to “dump” into the small intestine too quickly, which can lead to unpleasant symptoms.

Certain foods are more likely to cause bariatric dumping, including refined sugars, dairy products, and certain fatty and fried foods. While bariatric dumping is unpleasant, it can be managed and usually resolves within 1-2 years after surgery.

Types of Bariatric Surgeries That Can Cause Dumping Syndrome

Surgeries that change the anatomy of the digestive tract can lead to dumping syndrome. Many bariatric surgeries modify the size of the stomach and/or the small intestine. The following bariatric surgeries can cause dumping syndrome:

Gastric bypass surgery: Also known as a Roux-en-y, gastric bypass surgery is a weight loss surgery that cuts the stomach into the size of a small pouch. The modified stomach is then connected to the lower small intestine to decrease fat and calorie absorption.

Vertical sleeve gastrectomy: This procedure removes part of the stomach to help with weight loss. The stomach is cut into a tube or “sleeve,” therefore limiting the amount of food intake. In sleeve gastrectomy, dumping syndrome is described as a possibility, but not as common as in gastric bypass.

Bariatric Dumping Symptoms

Symptoms of dumping after bariatric surgery are divided into two phases: early and late. The early phase occurs within 30-60 minutes after eating. Causes of dumping in the early phase are due to food rapidly “dumping” into the small intestine.

The digestive system reacts to the small intestine stretching because it senses a mass of food that is too concentrated. In response, the digestive tract releases hormones that pull water from the bloodstream into the small intestine. This shift in fluid causes bloating and fullness, and also releases hormones that affect blood pressure and heart rate.

Frequent, rapid trips to the bathroom are one of the most uncomfortable side effects of bariatric dumping syndrome.

Symptoms of the early phase include:

  • Bloating
  • Feeling full, even after a small amount of food
  • Abdominal cramping or pain
  • Nausea and vomiting
  • Severe diarrhea
  • Sweating, flushing, or lightheadedness
  • Rapid heartbeat

The late phase of bariatric dumping occurs within 1-3 hours of eating. Symptoms develop within this time frame due to a decrease in blood sugar after a large surge of insulin (this is called reactive hypoglycemia). Eating foods that are simple carbohydrates or that are high in sugar are more likely to result in a rapid rise and fall in blood sugar.

Symptoms of the late phase include:

  • Weakness or fatigue
  • Flushing or sweating
  • Rapid heart rate
  • Shakiness
  • Dizziness, lightheadedness, fainting, or passing out
  • Mental confusion or loss of concentration
  • Feeling hungry

Symptoms in the late phase are alarming and may not always be related to dumping syndrome. If you have confusion, dizziness, fainting, or rapid heart rate and have not been diagnosed with dumping syndrome, seek immediate medical attention.

If you have symptoms that lead you to believe you have dumping syndrome, talk with your provider about ways to diagnose, manage, and treat your symptoms.

How Is Dumping Syndrome Diagnosed?

Your health care provider may use the following methods to diagnose bariatric dumping syndrome:

Medical history and evaluation - Your provider will conduct a medical history and review of  your symptoms. As bariatric surgery dumping is a common condition affecting post-bariatric surgery patients, a review of the symptoms alone may be sufficient in diagnosing dumping syndrome.

Glucose tolerance test - A rapid shift in blood sugar levels can be associated with dumping syndrome. Your provider may conduct an oral glucose tolerance test to measure the peak of your blood sugar levels at the peak time in which your symptoms begin.

Gastric emptying study - Your provider may order a gastric emptying test to determine the amount of time that food moves through the stomach and small intestine.

What Are Treatment Options for Dumping Syndrome After Bariatric Surgery?

The first line of treatment for bariatric dumping syndrome is diet. If following a strict diet does not ease the symptoms of dumping syndrome, your provider may recommend anti-diarrheal medication or another surgical procedure to modify the previous bariatric surgery.

Treatment of late dumping syndrome may be as simple as drinking a small amount of sugar one hour after eating to prevent reactive hypoglycemia. A small glass of orange juice may be sufficient to counteract the symptoms of lightheadedness, dizziness, rapid heart rate, mental confusion, and fainting. If drinking or eating a small amount of sugar does not improve these symptoms, seek medical help immediately.

Treatment of bariatric dumping syndrome may involve making small changes to your diet. Your provider and nutritionist can help guide you in improving your symptoms.

What Are Dietary Strategies to Help Improve Bariatric Dumping Syndrome?

Symptom management of dumping syndrome starts with maintaining a strict diet and optimizing nutrition. There are some key strategies to minimizing dumping symptoms.

  • Eat six small meals rather than three large meals a day. Smaller meals reduce the amount of stretch to the modified stomach and intestines.
  • Avoid drinking fluid with meals until at least 30 minutes after eating.
  • Rest after eating so you do not increase the rate of digestion through activity.
  • Eat protein-rich foods including meats, fish, and peanut butter. Also, eat complex carbohydrates such as fibrous whole grains and oats.
  • Increase fiber intake with foods high in fiber or supplements to delay carbohydrate absorption.
  • Take supplements to support your nutrient requirements. Your provider and nutritionist should help guide you to the appropriate supplementation to ensure adequate nutrient intake.
  • Be mindful of what you eat. Space is limited in your stomach so what you eat must provide as many nutrients as possible to support your body.
  • Plan your meals ahead of time so that you are not forced or swayed to eat a food that is likely to cause symptoms.
  • Avoid simple carbohydrates and refined sugars including sodas, candies, and table sugar. The natural sugars in dairy products may worsen your symptoms, so try dairy in small quantities at first.
  • Discuss with your provider whether or not alcohol may be consumed.
Avoid drinking fluids while eating to reduce the volume that your stomach and small intestine must hold at one time.

Dumping Syndrome is Unpleasant, But Does It at Least Help With Weight Loss?

It would seem that dumping syndrome would lead to more weight loss as the body is literally dumping out food before its nutrients can be absorbed. However, studies show this is not the case. One study examined whether patients were more likely to have better weight loss if they experienced dumping syndrome compared to patients who followed a strict diet and reported no dumping syndrome.

This study demonstrated that patients who followed strict behavioral control in diet were more likely to have better weight loss than  dumping syndrome patients. In short, dumping syndrome does not lead to more weight loss. However, following a strict diet after bariatric surgery is the greatest factor in achieving your weight loss goals.

Supplements are necessary to support your body’s nutrient requirements.

Striving for Improved Quality of Life

Bariatric surgery has shown to be an effective treatment of obesity. By following a strict diet, you may be able to control the unpleasant symptoms of dumping syndrome. Bariatric surgery aims to help improve your quality of life, but achieving a better quality of life requires you to follow your provider’s dietary recommendations.

Finding Support

The weight loss journey presents many challenges, and bariatric surgery is usually one of the first of many hurdles. Finding a support system to help you achieve your weight loss goals is helpful. Your provider, nutritionist, mental health professional, personal trainer, and/or support group are all people to lean on and seek encouragement from so that you can live your fullest life.

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Julia Rae Walker, RN, BSN, BA


Julia is an experienced critical care nurse with a background in pediatric and adult patient populations. Her passion is helping patients maximize their quality of life.

Gintas Antanavicius, MD, FACS, FASMBS

Medical Reviewer

Dr. G is a co-founder of BariBuilder. A US-based expert surgeon with over 10 years of bariatric experience, he regularly publishes research in medical journals like SOARD, Obesity Surgery, etc.