Dumping syndrome, also called rapid gastric emptying, is a condition that causes food to move from the stomach to the small intestine before the stomach has time to adequately digest it, especially high-sugar foods. In dumping syndrome, symptoms can occur 10-30 minutes after consuming food (early dumping syndrome) or one to three hours after consuming food (late dumping syndrome). Many people can experience both types, but some will experience only one or the other.
Dumping syndrome occurs as a complication of surgery in the stomach or esophagus. The most common causes include surgeries for weight loss (bariatric surgery) such as a new, smaller stomach pouch created through surgery (gastric bypass) or the removal of a portion of the stomach (gastrectomy), but can also include partial or full removal of the esophagus (esophagectomy) and other surgeries.
Another condition, gastroparesis (or delayed gastric emptying) is often caused by damage to the vagus nerve. However, in some cases, damage to the vagus nerve can cause rapid gastric emptying instead.
Dumping syndrome is one of the most common complications of bariatric surgery. Up to 50% of those who have had a gastrectomy experience this condition.1 It also occurs in approximately 10% of those who have had any type of gastric surgery.2
In early dumping syndrome, undigested food enters the small intestine, which draws in too much water from surrounding blood vessels and intestinal tissue. This can cause significant bloating and bowel cramps and lead to diarrhea, nausea, and vomiting, as well as symptoms in other parts of the body, such as light-headedness, dizziness, flushing, and an irregular heart rate.
In late dumping syndrome, a large amount of sugar enters the small intestine at once, which the body absorbs quickly. This causes the pancreas to release an excessive amount of insulin, leading to very low blood sugar levels (hypoglycemia). Symptoms such as hunger, fatigue, weakness, dizziness, sweating, and difficulty concentrating are common in addition to the gastrointestinal symptoms found in early dumping syndrome.
If your physician suspects dumping syndrome, they will look at your medical history – especially recent surgeries – and ask you questions about your symptoms. After this, there are several tests that can confirm a dumping syndrome diagnosis and determine severity of the condition.
Glucose challenge tests help your physician to determine whether your body is responding normally to glucose, since dumping syndrome typically causes low glucose levels. In this test, you drink a type of sugar (glucose) solution. One hour later, a health technician will measure your blood sugar levels.
Gastric emptying scans allow your health care team to measure the speed at which you digest food. For this test, you consume a tiny amount of radioactive material with a small meal, which allows technicians to monitor the rate at which it passes through your digestive system by periodically using a camera to check where the radioactive meal is. If it empties too quickly, then it can indicate dumping syndrome.
An upper gastrointestinal series involves consuming a barium drink in front of an x-ray machine after fasting. The barium is a chalky liquid that shows up on x-rays, allowing the technicians to see details in the gastrointestinal tract. This procedure is becoming less common.
Gastroscopy involves a physician using a small, flexible tube with a camera and a light (endoscope) to look at the upper parts of the digestive system, including the esophagus, stomach, and duodenum.
Dumping syndrome is typically a temporary effect of surgery, which resolves on its own within a few months. However, there are some treatments to help ensure adequate nutrition, avoid nutritional deficiencies, decrease symptoms of rapid gastric emptying, limit excessive weight loss, and encourage quick healing and recovery from the initial surgery.
Lifestyle and Dietary Changes
Specific dietary changes can greatly reduce symptoms from dumping syndrome. Eating smaller meals more frequently, such as six to eight small meals interspersed throughout the day can help decrease the load of food entering the small intestine. Try eating more foods that are high in complex carbohydrates and fibre, such as whole grains, vegetables, and legumes, as well as high-protein foods, such as meat, fish, eggs, nuts, cottage cheese, unsweetened yogurt, and tofu. These foods can slow down gastric emptying. Avoid simple carbohydrates and sugar, including white bread, juice, fluid milk (cheese, yogurt, and butter are typically okay to eat), honey, and anything with added sugar, such as candy, desserts, jams, and sweetened beverages to reduce the amount of sugar entering the blood at once.
Don’t drink large quantities of liquids with meals, because this can also trigger rapid gastric emptying by increasing stomach volume. However, make sure to drink plenty of water between meals to stay well-hydrated.
Talk to your physician about supplements, which might be necessary since bariatric surgery itself often limits absorption of certain nutrients. If you have dumping syndrome, you might require iron, calcium, and vitamin B12 supplements.3
Some general behaviour modifications, such as eating slowly and chewing well can also help to decrease symptoms. Adding fibre supplements to your meals might also help slow down gastric emptying.1
Dietary adjustments are often enough to reduce symptoms while the stomach heals from surgery, but in some cases medications might be necessary. A drug called octreotide (Sandostatin® LAR®), which is available in injectable form, can help to slow transit time, reducing symptoms of early and late dumping syndrome. Another medication, acarbose (Precose®), interferes with carbohydrate absorption, and is specifically useful in regulating blood sugar and preventing symptoms associated with low blood sugar in late dumping syndrome.
If dumping syndrome does not resolve on its own over time, or if dietary changes and medications are not effective, then surgery might be necessary. This can include reconstructive surgery or reversing gastric bypass, if applicable.
While symptoms from dumping syndrome can be very unpleasant and lead to nutritional deficiencies in some individuals, most cases resolve on their own in time. In addition, there are treatments available to reduce the impact of this condition.