There is a lack of recommendation regarding exploration and treatment of chronic diarrhea following gastric bypass, while it is a common side effect of this surgery. The electronic databases MEDLINE and EMBASE were searched until July 2018. Of the 553 articles identified, 35 articles were included. Intestinal bacterial overgrowth and pancreatic exocrine insufficiency are the main etiologies of diarrhea following gastric bypass. The diagnostic approach must begin by eliminating infectious causes of diarrhea. Exocrine pancreatic insufficiency can be diagnosed with fecal fat quantification or fecal elastase 1 level evaluation. A positive lactulose breath test confirms suspicion of small intestine bacterial overgrowth. In conclusion, we propose sequential exploration and treatment of the possible etiologies of diarrhea depending on clinical symptoms.
Keywords: Bariatric surgery; Diarrhea; Gastric bypass.