dumping syndrome

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.

Anatomic structures of the stomach are divided into the cardia, fundus, body, and pylorus. The fundus serves as the reservoir for ingested meals, while the distal stomach churns and mixes with digestive enzymes and initiates the digestive process. Once the foods are processed, the pylorus releases the food in a controlled fashion downstream into the duodenum.

The capacity of the stomach in adults is approximately 1.5-2 liters, and its location in the abdomen allows for considerable distensibility. Gastric motility is controlled by myogenic (intrinsic), circulating hormonal, and neural activity (gastric plexus, myenteric plexus, sympathetic and parasympathetic nerves). Alterations in gastric anatomy after surgery or interference in its extrinsic innervation (vagotomy) may have profound effects on the gastric reservoir and pyloric sphincter mechanism and, in turn, alter gastric emptying. These effects, for convenience, have been termed postgastrectomy syndromes.

Postgastrectomy syndromes include small capacity, dumping syndrome, bile gastritis, afferent loop syndrome, efferent loop syndrome, anemia, and metabolic bone disease. Postgastrectomy syndromes are iatrogenic conditions that may arise from partial gastrectomies, independent of whether the gastric surgery was initially performed for peptic ulcer disease, cancer, or weight loss (bariatric). The surgical procedures include Billroth-I, Billroth-II, and Roux-en-Y.<sup>[1]

http://emedicine.medscape.com/article/173594-overview</sup>