Evaluation of chronic diarrhea and irritable bowel syndrome with diarrhea in adults in the era of precision medicineSchiller, Lawrence R., MD, MACG1,2American Journal of Gastroenterology: May 2018 - Volume 113 - Issue 5 - p 660–669 doi: 10.1038/s41395-018-0032-9 CLINICAL AND SYSTEMATIC REVIEWS Buy Abstract Author InformationAuthors Article MetricsMetrics Chronic diarrhea is a common clinical problem, affecting roughly 5% of the population in any given year. Evaluation and management of these patients can be difficult due to the extensive differential diagnosis of this symptom. Many patients with chronic diarrhea have structural problems, such as inflammatory bowel disease or celiac disease, that can be readily identified. Others do not, and often are given a diagnosis of irritable bowel syndrome with diarrhea (IBS-D). When based on generally accepted clinical criteria, a diagnosis of IBS-D identifies a group of patients who are unlikely to have disorders producing anatomical changes in the gut. It is less clear that a diagnosis of IBS-D identifies a specific pathophysiology or leads to better management of symptoms. Disorders such as small intestinal bacterial overgrowth, bile acid malabsorption, food intolerance, and motility disorders may account for symptoms in patients with IBS-D. More effective tests are being developed to identify the clinical problems underlying IBS-D and may lead to more specific diagnoses that may improve the results of therapy. Application of the principles of precision medicine (identifying a specific mechanism for disease and applying treatments that work on that mechanism) should lead to more expeditious diagnosis and treatment for patients with chronic diarrhea including IBS-D, but currently is limited by the availability of sufficiently sensitive and specific tests for underlying mechanisms that can predict response to treatment. 1Baylor University Medical Center, Dallas, TX, USA. 2Texas A & M College of Medicine, Dallas, TX, USA. Correspondence: L.R.S. (email: LRSMD@aol.com) Received 20 November 2017; revised 13 January 2018; accepted 21 January 2018; published online 1 May 2018 © The American College of Gastroenterology 2018. All Rights Reserved.