Dumping Syndrome After Gastric Sleeve

Dumping syndrome: causes, symptoms, and what can be done

Dumping syndrome can occur after someone has a portion of their stomach removed or bypassed (such as the gastric sleeve surgery). The symptoms can be uncomfortable and concerning but there are simple modifications that can lead to improvements.

This article will explain what dumping syndrome is, what causes it to occur, which symptoms you should be aware of, and what you should do if you are experiencing symptoms.

What is dumping syndrome?

Dumping syndrome is a group of symptoms that can occur after eating in people who have had gastric surgery. This may include someone who has had a gastrectomy (removal of a portion of the stomach), esophagectomy (removal of a portion of esophagus), or bariatric surgery.

The most common bariatric surgeries that can lead to dumping syndrome include the Roux-en-Y gastric bypass (RYGB) and the gastric sleeve (GS).

The symptoms can range from mild to severe. Symptoms are related to the uncontrolled manner in which food moves from the stomach quickly into the small intestine.

Most people can expect some dumping syndrome symptoms after RYGB since there is a bowel bypass component of the surgery. However, dumping syndrome also can occur after the GS procedure.

The symptoms can be uncomfortable and concerning but are not life-threatening. Fortunately, diet modifications can help prevent or reduce the symptoms experienced for most people.

How common is dumping syndrome?

The prevalence of dumping syndrome has been reported to be as much as 85% of bariatric patients. A more recent study confirmed that almost 85% of RYGB and SG patients experienced symptoms of early dumping. Late dumping was not as prevalent (28-36% for RYGB and SG, respectively).

Dumping Syndrome After Gastric Sleeve Bari Life

What causes dumping syndrome?

Under usual circumstances, it takes several hours for food to move from the stomach to the small intestine. However, after gastric surgery, the food moves through the stomach in a less controlled way and much more quickly.

Dumping Syndrome After Gastric Sleeve Bari Life

Additionally, gastric surgery reduces the volume that the stomach can hold at any one time.

Dumping syndrome occurs after eating a meal and it is described as early stage dumping or late stage dumping.

Early-stage dumping vs Late-stage dumping

In early-stage dumping, undigested food passes quickly through the stomach. This quick passage of food from the stomach to the small intestine causes a fluid shift.

Fluid from the blood vessels moves to the small intestine causing the individual to feel more full or bloated. The influx of fluid can lead to additional symptoms like cramping and diarrhea.

Dumping Syndrome After Gastric Sleeve Bari Life

Additionally, people may experience tachycardia (elevated heart rate) or feel faint because of less fluid in the blood vessels. These symptoms typically occur 30-60 minutes after a meal.

In late-stage dumping, the quick delivery of partially digested foods to the small intestine causes a rise in blood sugar that is faster than normal. This signals the pancreas to release insulin and the quick release of insulin can ultimately lead to hypoglycemia (low blood sugar).

This is also referred to as postprandial hyperinsulinemic hypoglycemia or reactive hypoglycemia. Late dumping may not be seen in the first year immediately after surgery.

Does dumping syndrome vary depending on the bariatric procedure?

Since the RYGB surgery is restrictive with some malabsorption, it makes sense that some level of dumping syndrome may occur.

The RYGB procedure involves creating a small gastric pouch and then connecting it lower down the small intestinal tract (jejunum), bypassing a portion of the proximal intestines (duodenum).

This also means that the pylorus, which controls the movement of food to the small intestine is bypassed. The portion of the intestine that is bypassed still provides bile and pancreatic juices to mix with food in the jejunum.

The sleeve gastrectomy (SG) procedure is much more common now. It is a restrictive procedure without malabsorption. This procedure involves making the stomach smaller to limit food intake but the nutrients are absorbed normally.

Dumping Syndrome After Gastric Sleeve Bari Life

About 85% of people having undergone RYGB or SG report symptoms of early dumping. Research has found reactive hypoglycemia to be just as common after SG compared to RYGB, although people that had an RYGB could be at greater risk of more severe hypoglycemic events.

It’s a common thought that only RYGB patients battle dumping syndrome; however, it’s a common side-effect of bariatric surgery whether you’ve had the RYGB or SG.

What are the symptoms of dumping syndrome?

Symptoms of dumping syndrome can vary depending on whether you are experiencing early or late phase dumping.

Symptoms of early dumping are related to the release of gut hormones and the influx of water into the small intestine. As a result, the symptoms involve the gastrointestinal (GI) tract.

The symptoms of late dumping are those associated with hypoglycemia (low blood sugar). You should be familiar with symptoms of hypoglycemia which may include:

  • Feeling weak
  • Fatigue
  • Lightheaded
  • Dizziness
  • Chills
  • Sweating
  • Nervousness, anxious, or shaky
  • Hunger

Below is a list of symptoms associated with early and late dumping syndrome:

Early dumping (30-60 minutes post meal)Late dumping (1-3 hrs post meal)
Feel full (even after small meal)Heart palpitations
Stomach growlingConfusion
Abdominal crampsFainting
High heart rate
Heart palpitations

How is dumping syndrome diagnosed?

If you are experiencing any of these symptoms after surgery, you should discuss this with your physician.

Reports of symptoms that coincide with meal times (30-60 minutes after a meal) are often enough to diagnose early dumping. In some cases additional testing may be needed.

An oral glucose tolerance test or gastric emptying study test are two options for testing. Your physician would need to order any additional testing.

To confirm a diagnosis of late dumping (postprandial hyperinsulinemic hypoglycemia), one must be having symptoms a year out from the surgery, keep a food journal, and have confirmatory lab work and testing.

Does dumping syndrome ever go away?

The good news is that dumping syndrome can go away. Most experience improvements over time with proper diet modifications. Changes to the diet are the initial approach to treat dumping syndrome.

What changes should I make to my diet?

There are several diet modifications that can help mitigate the symptoms associated with dumping syndrome. These include:

  • Eating 6 small meals daily
  • Eating small portions as suggested in the bariatric diet
  • Cutting food into small pieces and chewing well
  • Stopping eating when you feel full
  • Avoiding refined sugars
  • Eating complex carbs (if you are in phase 4/stabilization diet)
  • Adding fiber
  • Drinking fluids only 30 minutes before or after a meal
  • Avoiding alcohol
  • Avoiding dairy products (if you do not tolerate dairy)

Some of these tips should sound familiar to you already. Many of the diet modifications for dumping syndrome are already part of the post-bariatric procedure diet.

For example, high sugar items like desserts are more likely to lead to GI symptoms associated with dumping but desserts are already on the avoid list of foods. Thus, experiencing symptoms after eating a food that should be avoided, may serve as negative reinforcement.

The following is a list of foods to avoid eating if you are experiencing dumping syndrome:

[table id=22 /]

As a reminder, you will want to be sure you are following portion sizes recommended for you and emphasize getting protein in first. Additionally, getting a minimum of 64 ounces (8 cups) of fluid daily is recommended but it should be consumed 30 minutes before or after your meal.

Below is a list of foods that you can eat after a RYGB or SG:

[table id=25 /]

What if I still have symptoms of dumping syndrome after changing my diet?

Most people see improvement with diet changes but there are a few who don’t. You should call your physician if you don’t see improvement within 2-4 weeks of diet modifications.

In this case, there are a couple of medications that may be prescribed. For late dumping, acarbose may help to slow sugar absorption. Another medication, octreotide, may help to slow gastric emptying. Your physician will assess whether you are a good candidate for either medication.


In summary, nutrition therapy prescribed after your bariatric surgery should help prevent the symptoms associated with dumping syndrome. In some cases, further adjustments to the diet may be needed.

Be sure to discuss with your physician if you are experiencing symptoms of dumping syndrome. Working with your physician and a Registered Dietitian is recommended as those who continue to follow up with their team see the best outcomes after bariatric surgery.


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