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Gastric dumping syndrome, or rapid gastric emptying is a condition where ingested foods bypass the stomach too rapidly and enter the small intestine largely undigested. It happens when the small intestine expands too quickly due to the presence of hyperosmolar (having increased osmolarity) contents from the stomach. This causes symptoms due to the fluid shift into the gut lumen with plasma volume contraction and acute intestinal distention. "Early" dumping begins concurrently within 15 to 30 minutes from ingestion of a meal.〔 Symptoms of early dumping include nausea, vomiting, bloating, cramping, diarrhea, dizziness, and fatigue. "Late" dumping happens one to three hours after eating. Symptoms of late dumping include weakness, sweating, and dizziness. Many people have both types. The syndrome is most often associated with gastric bypass (Roux-en-Y) surgery. 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." ==Diagnosis== Physicians 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. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「gastric dumping syndrome」の詳細全文を読む スポンサード リンク
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