A disorder affecting the small intestine. It is caused by the stasis of food and subsequent overgrowth of bacteria in a portion of the small intestine that is unintentionally bypassed as a complication of abdominal surgery or as a sequela of gastrointestinal disorders which impede effective motility. Clinical signs include bloating, abdominal pain, diarrhea and weight loss. If untreated, the clinical course progresses to malabsorption of fats, vitamin B12 and calcium, the latter which predisposes to nephrolithiasis and osteoporosis.