What Is Dumping Syndrome?

Dumping syndrome, also known as rapid gastric emptying, is a condition in which you experience gastrointestinal or vasomotor symptoms because the food that you eat moves too quickly from your stomach into your ​small intestine. Symptoms begin when you eat a meal, particularly from a menu with a high glucose (sugar) content.​​​​

Dumping syndrome is most often seen in people who have had bariatric (weight loss), esophageal, or gastric surgery. It can also occur in people who have pancreatic insufficiency or were recently diagnosed with diabetes. Sometimes, though, the cause is unknown.

Estimates of the number of people who experience dumping syndrome following gastric surgery range from 20% to 50%. Only 1% to 5% of patients experience more severe symptoms. The type of surgery you have also influences your risk of developing dumping syndrome.

How Long Dumping Syndrome Lasts

In general, the symptoms of dumping syndrome tend to improve over time. Approximately three-quarters of people who undergo gastric bypass will experience symptoms immediately following the procedure, but most people find that their symptoms disappear over the next 15 to 18 months.

Dumping syndrome is broken down into two types: early dumping syndrome and late dumping syndrome.

Most people with dumping syndrome experience the early form, while only about a quarter experiences the late-type. A very small minority of people have both.

The sub-types also manifest with different types of symptoms, with early dumping symptoms being both gastrointestinal and vasomotor, while late dumping symptoms tend to be mostly vasomotor.

Why Dumping Happens 

In normal digestion, the stomach empties its contents into the duodenum, the upper part of the small intestine, in a controlled manner in which large food particles are screened out. For some people, changes in the anatomy of the GI tract as a side effect of surgery results in dysfunction of this system.

The stomach being smaller, or damage to the pylorus—the part of the body that is responsible for acting as a dam—results in large amounts of stomach contents and larger food particles being released rapidly into the duodenum.

This swift emptying results in pronounced changes in blood glucose levels and an increase in certain hormones, which then contribute to cardiovascular symptoms and symptoms associated with hypoglycemia.

Late dumping syndrome results more exclusively from changes in blood glucose and insulin levels. In late dumping syndrome, symptoms are triggered because too much sugar is released into the small intestine too quickly.

This spike results in an increase in blood glucose levels, which triggers the pancreas to ramp up the secretion of insulin. This insulin release then triggers a drop in blood glucose levels—resulting in symptoms of hypoglycemia.

Dumping Syndrome Symptoms

Early Dumping: In early dumping syndrome, symptoms typically start approximately 10 to 30 minutes after eating a meal:

• Abdominal cramps
• Nausea
• Urgent diarrhea
• Vomiting
• Blushing of face or skin
• Feeling light-headed or dizzy
• Racing heart or irregular heartbeat
• Sweating
• Weakness

Late Dumping: Symptoms of late dumping syndrome generally occur one to three hours after eating a meal:

• Trouble concentrating
• Fainting
• Fatigue
• Feeling light-headed or dizzy
• Hunger
• Rapid heartbeat or palpitations
• Sweating
• Weakness

Diagnosis

Dumping syndrome is diagnosed based on your medical history and symptoms. You may be asked to fill out a questionnaire that assigns different points to various symptoms to help. This can help tease out whether your signs indicate dumping syndrome or another cause. 

In some cases, your healthcare provider will order further testing, which may include: 

• Oral glucose tolerance test: This test requires fasting for at least 10 hours before drinking a glucose solution. Your blood sugar, hematocrit, heart rate, and blood pressure are monitored for three hours.
• Gastric emptying scan: This test involves eating a bland meal with a small amount of radioactive material. A camera outside the body scans the abdomen to track the radioactive material and see how fast your stomach empties. This test can take up to four hours. 
• Upper gastrointestinal (GI) endoscopy: This test is done under sedation. A thin, flexible tube with a lighted camera is threaded through your mouth and throat to examine the esophagus, stomach, and small intestine. Tissue samples may be taken to rule out other causes of your symptoms. 
  

Self-Care Dos and Don'ts

Most of the self-care recommendations for dumping syndrome involve changes in the way you eat, although you also might find that you can reduce feeling light-headed or faint if you lie down, face up, for 30 minutes after meals.

Dumping Syndrome Treatment

If your symptoms persist in spite of making dietary changes, speak with your healthcare provider. People who have more significant dumping syndrome symptoms are at risk for eating avoidance and nutritional deficiencies.

Your practitioner will evaluate you and advise you as to the best course of action. If you have late dumping syndrome, your medical professional might recommend you increase your fiber intake through food or a supplement, in order to slow down the absorption of glucose and reduce the chance of hypoglycemia.

Another option for either type is for your healthcare provider to prescribe one of the medications that are available for treating dumping syndrome.

In extremely severe cases, a surgical procedure might be considered. However, as most cases of dumping syndrome improve over time, surgery would most likely not even be considered for at least one year following the original gastric procedure.