Gastric dumping syndrome

Gastric dumping syndrome, or rapid gastric emptying, happens when the lower end of the small intestine, the jejunum, fills too quickly with undigested food from the stomach. "Early" dumping begins during or right after a meal. Symptoms of early dumping include nausea, vomiting, bloating, cramping, diarrhea, dizziness and fatigue. "Late" dumping happens 1 to 3 hours after eating. Symptoms of late dumping include weakness, sweating, and dizziness. Many people have both types.

It is speculated that "early" dumping is associated with difficulty digesting fats while "late" dumping is associated with carbohydrates.

Rapid loading of the small intestine with hypertonic stomach contents can lead to rapid entry of water into the intestinal lumen. Osmotic diarrhea, distension of the small bowel (leading to crampy abdominal pain), and hypovolemia can result.

In addition, people with this syndrome often suffer from low blood sugar, or hypoglycemia, because the rapid "dumping" of food triggers the pancreas to release excessive amounts of insulin into the bloodstream. This type of hypoglycemia is referred to as "alimentary hypoglycemia".

Causes

Dumping syndrome is most common in patients with certain types of stomach surgery, such as a gastrectomy or gastric bypass surgery, that allow the stomach to empty rapidly. Dumping syndrome can also occur as a result of complications after a cholecystectomy (gallbladder removal).

Patients with Zollinger-Ellison syndrome, a rare disorder involving extreme peptic ulcer disease and gastrin-secreting tumors in the pancreas, may also have dumping syndrome.

Dumping is also common for esophageal cancer patients who have had an esophagectomy; surgery to remove the cancerous portion of their esophagus. The stomach is pulled into the chest and attached to what remains of the esophagus, leaving a short digestive tract. Both early and late dumping syndrome can occur in the same patient.

Finally, patients with connective tissue conditions such as Ehlers-Danlos syndrome can experience "late" dumping as a result of decreased motility.

Diagnosis

Doctors diagnose dumping syndrome primarily on the basis of symptoms in patients who have had gastric surgery. Tests may be needed to exclude other conditions that have similar symptoms. Two ways of determining if a patient has dumping syndrome include Barium fluoroscopy and radionuclide scintigraphy.

In the first procedure, a contrast of barium-labeled medium is ingested, and x-ray images are taken; early dumping can be easily recognized by premature emptying of the contrast medium from the stomach.

The second method, scintigraphy (or radionuclide scanning), involves a similar procedure in which a labeled medium containing ^99mTc (or other radionuclide) colloid or chelate is ingested. The 99mTc isotope decays in the stomach, and the gamma photons emitted are detected by a gamma camera; the radioactivity of the area of interest (the stomach) can then be plotted against time on a graph. Patients with dumping syndrome generally exhibit steep drops in their activity plots, corresponding to abnormally rapid emptying of gastric contents into the duodenum.

Treatment

Dumping syndrome is largely avoidable by avoiding certain foods which are likely to cause it, therefore having a balanced diet is important. Treatment includes changes in eating habits and medication. People who have gastric dumping syndrome need to eat several small meals a day that are low in carbohydrates, especially omitting simple sugars (candy, desserts, ice cream), and should drink liquids between meals, not with them. People with severe cases take medicine such as cholestyramine or proton pump inhibitors (such as pantoprazole) to slow their digestion. Doctors may also recommend surgery.