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Gastric Bypass Dumping: Symptoms, Signs, and Treatments

Gastric Bypass Dumping: Symptoms, Signs, and Treatments

Gastric bypass dumping syndrome is an unfortunately common experience for many. It comes with a long list of symptoms that include diarrhea and nausea. Fortunately, it is preventable and manageable as you settle into life after surgery.

Gastric bypass surgery is a highly effective tool for fighting obesity

Obesity continues to be a growing epidemic in the United States. There are numerous methods people have tried tackling this health issue; many with disappointing results. The gastric bypass weight loss surgery, also known as Roux-en-Y, has become a common choice for many patients struggling with obesity.

Although the surgery is not for everyone, the appropriate candidate can expect 60 to 80 percent excess weight loss. This procedure changes how food is directed through the stomach and the small intestine.

Visual sketch of a digestive system after a gastric bypass

This two-part surgery starts with a reduction of the stomach by creating a smaller stomach pouch. This pouch is close to the size of an egg, and its goal is to dramatically restrict food intake.

With the pouch, food moves along on a different path since it bypasses most of your stomach and the first section of the small intestine, the duodenum. At consumption, food passes directly into the middle section of the small intestine (jejunum) from the new stomach pouch. Since there is less food digestion and the intestine is not absorbing as many calories and nutrients, significant weight loss is expected.

The alteration of the digestive tract has shown to control hunger, increase satiety, and help reverse type 2 diabetes. Due to its more complex nature, it is crucial for patients to sustain proper nutrition - especially adequate protein intake and comply with a strict vitamin/mineral supplementation regimen which is continuous, life-long commitment.

Non-compliance with these needs can lead to consequences such as iron, calcium, vitamin B12, and folic acid deficiencies. These can hinder reaching and/or maintaining a healthy weight and a comfortable lifestyle. Patients should follow up with their healthcare providers and seek a support group for optimal lasting results.

Dumping syndrome is a common issue for gastric bypass patients

Dumping syndrome is a common condition when food literally gets “dumped” from the new stomach pouch into the small intestine without being digested.

Our pyloric valve is located at the end of our stomach. This valve controls the rate of digested food emptying out of the stomach to the small intestine. With the gastric bypass, the pyloric valve is bypassed and no longer in use so the patient needs to carefully monitor how food is consumed.

Without this monitoring, gastric bypass dumping syndrome is likely to occur. Most patients will experience early dumping symptoms: symptoms that occur 10 to 30 minutes post-meal. Others will experience late dumping symptoms: one to three hours post-meal. Some may experience both early and late. How and what you eat makes a big difference in how you will feel soon after.

Early dumping symptoms: occur 10 to 30 minutes post-meal
Late dumping symptoms: occur one to three hours post-meal

Dumping syndrome symptoms include diarrhea, nausea, and more

Early dumping occurs when a concentrated mass of food moves rapidly from the new stomach pouch into the small intestine which can release gut hormones and disrupt the body. Early dumping signs and symptoms include:

  • Diarrhea
  • Nausea
  • Vomiting
  • Abdominal cramps
  • Feeling bloated
  • Rapid heart rate
  • Lightheadedness
An onset of dumping will make you feel uncomfortable.

Late dumping usually happens due to an immediate drop in blood sugar level, also known as reactive hypoglycemia, where the body releases large amount of insulin to absorb the sugars “dumped” into the small intestine.

If these symptoms persist, you can confirm by measuring your blood sugar level in the lab or even at home. Ask your healthcare provider for more information. Late dumping signs and symptoms include:

  • Fatigue
  • Sweating
  • Fainting
  • Heart palpitations
  • Tremors

Dumping syndrome treatment and prevention orients around managing your diet

Many times, the quality and/or quantity of food can determine whether or not you will experience dumping. Foods high in simple carbohydrates, such as white flour, table sugar, or sugar from fruit are usually the main culprits to make you feel uncomfortable.

Here are some foods you could consider adding to your diet to help minimize the onset of gastric bypass dumping:

  • Nutrient dense foods such as lean protein and fat
  • High fiber foods such as non-starchy vegetables
  • Complex carbohydrates such as whole grain products
Fish is a good option as a nutrient dense, high protein food.

And some other tips:

  • Consume 6 smaller meals and pace yourself by eating slower
  • Do not drink with meals - wait at least 30 minutes post-meal
  • If possible, lie down for 30 minutes post-meal to help control food emptying from the stomach
  • Avoid dairy products if you find that they cause problems
Try avoiding dairy products, like milk, to help prevent dumping.

If these kinds of modifications to your diet do not help with late dumping, try consuming a small amount of sugar - about 4 ounces via orange juice - about one hour after your meal in order to help prevent symptoms.

In summary: planning, protein, and slow eating are keys to success

Plan ahead of time

When hunger hits while at work and proper food choices are not readily available, we tend to gravitate towards the “bad” food such as the snacks at the vending machine or the closest fast food restaurant or convenience store. Packing meals and keeping a supply of appropriate snacks can help you stay on track.

Review restaurant menus ahead of time to make sure you come prepared.

When you are eating out with your friends, review the menu and look for healthy options such as roasted, steamed, baked protein choices along with vegetables in lieu of sides high in starch (ex. potatoes and rice) ahead of time. Knowing what you want to order before arriving will help you steer away from the carbohydrate and fat dense foods.

Protein, protein, protein!

Remember that your new stomach can hold about an ounce of food - imagine the size of a small egg. You want to make sure what you eat is worth it and will only provide nutritional benefits, not misery.

Eating high protein, nutrient dense foods such as lean meats, nuts, beans, tofu, eggs, protein supplements, dairy products (if tolerable), and non-starchy vegetables should be your first priority when choosing your meals. Since protein takes longer to digest, it will help you stay full longer. On the other hand, a bowl of pasta is broken down much quicker which will not satisfy your hunger and will lead you to overeat.

Eggs are another good source of protein

Eat slower and focus on your meal

Many of us are not mindful of how quickly we eat our meals. Find ways to slow you down: use smaller utensils, count the number of bites, avoid watching TV. Remember that drinking with meals is a likely cause of dumping. Put away your beverage and drink once you feel comfortable - usually at least 30 minutes after the meal.

As terrible as gastric bypass dumping is, you can also see it as a blessing in disguise. You will recognize and learn very quickly what foods and poor eating habits to avoid. Hopefully, this temporary phase after surgery will encourage you to take better ownership of your health and continue to fuel your body with appropriate nutrition, exercise, and support.

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Eun Jung Park, MS, RD


Eun Jung Park is a registered dietitian with over 10 years experience working in various clinical settings. She graduated from New York University with an Master of Science in Nutrition and Dietetics.

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.