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Dumping syndrome is a group of signs and symptoms that develops most often in people who have had surgery to remove all or part of their stomach, or in whom much of their stomach has been surgically bypassed to help lose weight. Also called rapid gastric emptying, dumping syndrome occurs when the undigested contents of your stomach are transported or "dumped" into your small intestine too rapidly. Common symptoms include abdominal cramps and nausea.

Most people with dumping syndrome experience signs and symptoms soon after eating. In other people, they may occur later — one to three hours after eating — and they can range from mild or moderate to severe and debilitating.

Most of the time, dumping syndrome improves on its own without medical treatment, or by adjusting your diet. In more serious cases of dumping syndrome, you may need medications or surgery.

When signs and symptoms occur during a meal or within 15 to 30 minutes following a meal, they may include:

• Nausea
• Vomiting
• Abdominal pain, cramps
• Diarrhea
• Dizziness, lightheadedness
• Bloating, belching
• Fatigue
• Heart palpitations, rapid heart rate

When signs and symptoms develop later, they may include:

• Sweating
• Weakness, fatigue
• Dizziness, lightheadedness
• Shakiness
• Feelings of anxiety, nervousness
• Heart palpitations, rapid heart rate
• Fainting
• Mental confusion

Some people experience both early and late signs and symptoms. Conditions such as dizziness and heart palpitations can occur either early or late — or both. No matter when problems develop, however, they may be worse in the aftermath of a high-carbohydrate meal, especially one that's rich in sugars such as sucrose (table sugar) or fructose (fruit sugar).

Some people also experience low blood sugar (hypoglycemia), related to excessive levels of insulin delivered to the bloodstream as part of the syndrome. Insulin influences your tissues to take up the sugar present in your bloodstream.

In dumping syndrome, food and juices from your stomach move to your small intestine in an unregulated, abnormally fast manner. This accelerated process is most often related to changes in your stomach associated with surgery. For example, when the opening (pylorus) between your stomach and the first portion of the small intestine (duodenum) has been damaged or removed during an operation, the syndrome may develop.

Dumping syndrome may occur in up to 15 percent of people who have had stomach surgery. It develops most commonly one to six months after surgery, and the greater the amount of stomach removed or bypassed, the more likely that the condition will be severe. It sometimes becomes a chronic disorder.

Gastrointestinal hormones also are believed to play a role in this rapid dumping process.

Several types of stomach surgery increase your risk of dumping syndrome. These include:

• Gastrectomy, in which a portion or all of your stomach is removed. It typically involves removing the pylorus.
• Gastroenterostomy or gastrojejunostomy, in which your stomach is surgically connected directly to your small intestine about two feet beyond the pylorus, thus bypassing the pylorus. Doctors sometime perform this operation in people with cancer of the stomach.
• Vagotomy, in which the nerves to your stomach are cut in order to lower the levels of acid manufactured by your stomach.
• Fundoplication, which is an operation sometimes performed on people with gastroesophageal reflux disease. It involves wrapping the upper portion of your stomach around the lower esophagus to apply pressure that reduces the reflux of gastric contents into the esophagus. However, on rare occasions, certain nerves to the stomach can unintentionally be damaged during surgery and lead to dumping syndrome.
• Gastric bypass surgery (Roux-en-Y operation), which is often performed in people who are morbidly obese. It surgically creates a smaller stomach pouch that's smaller than the entire stomach, meaning you're no longer able to eat as much as you once did, resulting in weight loss.

Certain underlying conditions also may make you more susceptible to dumping syndrome. These conditions include:

• Diabetes
• Gastroesophageal reflux disease (GERD), in which the contents of your stomach move back into your esophagus
• Zollinger-Ellison syndrome, which causes severe peptic ulcers

Contact your doctor if you develop signs and symptoms that might be due to dumping syndrome even if you have not had surgery. If you've already been diagnosed with this syndrome, keep your doctor informed on how well your treatment is working. Whenever symptoms worsen, talk to your doctor.

Because poor dietary choices can worsen signs and symptoms, your doctor may refer you to a registered dietitian to help you create the most appropriate eating plan. The guidance provided by a registered dietitian may be particularly important if you have lost large amounts of weight due to the syndrome.

Your doctor can diagnose dumping syndrome by taking a careful medical history and then evaluating your signs and symptoms. If you have undergone stomach surgery, that may help lead your doctor to a diagnosis of dumping syndrome.

Because low blood sugar is sometimes associated with dumping syndrome, your doctor may order a test to measure your blood sugar level at the peak time of your symptoms to help confirm the diagnosis.

In people with severe cases of dumping syndrome, marked weight loss and malnutrition may occur. Sometimes people who lose a lot of weight may also develop a fear of eating, related to the discomfort associated with the rapid dumping of undigested food. They may also avoid outdoor physical activity in order to stay close to a toilet. Some have difficulty keeping a job because of their chronic symptoms.

Most cases of dumping syndrome improve without any treatment, typically in several months to about a year after signs and symptoms begin. However, if they don't improve on their own — or if you want relief from symptoms soon after they appear — your doctor may advise one or more treatment options to slow the emptying of your stomach's contents. The choices for managing dumping syndrome include dietary changes, medications and surgery.

Dietary changes
Adjusting your diet may relieve your symptoms. Here are some strategies that your doctor may recommend:

• Eat smaller meals. Try consuming about six small meals a day rather than three larger ones.
• Avoid fluids with meals. Drink liquids only between meals.
• Change the makeup of your diet. Consume more low-carbohydrate foods. In particular, concentrate on a diet low in simple carbohydrates such as sugar (found in sweets like candy, cookies and cakes). Read labels on packaged food before buying, with the goal of not only avoiding foods with sugar in their ingredients list, but also looking for (and staying away from) alternative names for sugar, such as glucose, sucrose, fructose, dextrose, honey and corn syrup. Artificial sweeteners are acceptable alternatives. Consume more protein in your diet, and adopt a higher fiber diet.
• Increase pectin intake. Pectin is found in many fruits such as peaches, apples and plums, as well as in some fiber supplements. It can delay the absorption of carbohydrates in the small intestine.
• Stay away from acidic foods. Tomatoes and citrus fruits are harder for some people to digest.
• Use low-fat cooking methods. Prepare meat and other foods by broiling, baking or grilling.
• Consume adequate vitamins, iron and calcium. These can sometimes become depleted in the aftermath of stomach surgery. Discuss this nutritional issue with a registered dietitian.
• Lie down after eating. This may slow down the movement of food into your intestines.

Even with dietary changes, you may continue to experience severe symptoms associated with dumping syndrome.

Medications
Your doctor may prescribe certain medications to slow the passage of food out of your stomach, and relieve the signs and symptoms associated with dumping syndrome. These drugs are most appropriate for people with severe signs and symptoms, and they don't work for everyone. 

The medications that doctors most frequently prescribe are:

• Acarbose. This medication delays the digestion of carbohydrates. Doctors prescribe it most often for the management of type 2 diabetes, and it has also been found to be effective in people with late-onset dumping syndrome. Side effects may include sweating, headaches, pallor, sudden hunger and weakness.
• Octreotide (Sandostatin). This anti-diarrheal drug can slow down the emptying of food into the intestine. You take this drug by injecting it under your skin (subcutaneously). Be sure to talk with your doctor about the proper way to self-administer the drug, including optimal choices for injection sites. Long-acting formulations of this medication are available. Because octreotide carries the risk of side effects (diarrhea, bulky stools, gallstones, flatulence, bloating) in some people, doctors recommend it only for people who haven't responded to other treatments.

Surgery
Doctors use a number of surgical procedures to treat severe cases resistant to more conservative approaches. Most of these operations are reconstructive techniques, such as reconstructing the pylorus, or they're intended to reverse gastric bypass surgery.

You can't prevent dumping syndrome. However, measures such as dietary adjustments may prevent recurrences of your symptoms and minimize their severity.