Blind loop syndrome

Blind loop syndrome, also known as stagnant loop syndrome, occurs when the normal bacterial population of the small intestine grows to numbers large enough to significantly disrupt the normal processes of digestion and absorption, sometimes together with an overgrowth of harmful bacteria that do not normally live there. The condition arises when bacterial colonies in the upper gastrointestinal tract grow out of control or change in composition, placing a burden on the small intestine's normal function, and it can lead to vitamin B12 deficiency, fat malabsorption with steatorrhea, deficiencies of fat-soluble vitamins, and injury to the intestinal wall.