Curr Gastroenterol Rep. 2023 Dec 30. doi: 10.1007/s11894-023-00909-1.Online ahead of print.

Christine L Frissora ¹, Lawrence R Schiller ²

Author information

¹Division of Gastroenterology and Hepatology, The Weill Medical College of Cornell University, 1283 York Avenue, Floor 9, New York, NY, US, 10021. cfrissor@med.cornell.edu.

²Department of Medical Education, Texas A&M University School of Medicine, Dallas Campus, and Chair, Institutional Review Boards for Human Subject Protection, Baylor Scott & White Research Institute, Dallas, TX, US.

Abstract

Purpose of review: Irritable bowel syndrome with diarrhea (IBS-D) is diagnosed when chronic symptoms of abdominal pain accompany loose stools, and alarm features, such as fever, anemia, rectal bleeding, and weight loss are absent. This combination of symptoms makes structural disorders, such as inflammatory bowel disease or cancer, unlikely, but does not exclude other conditions that cause these symptoms. The question is whether making a "positive diagnosis" of IBS-D based on symptoms alone and instituting therapy based on that diagnosis still makes sense.

Recent findings: Clinical observations suggest that at least two-thirds of cases of IBS-D can be explained by three mechanisms: a) food intolerances (~ 30-40%), b) bile acid diarrhea (~ 20-30%), and c) disturbed microbial flora (~ 15-20%). Other conditions that are less frequent but can cause IBS symptoms or be confused with IBS include: celiac disease, microscopic colitis, mastocytosis/mast cell activation, and drug side-effects. Many cases of IBS-D have a discoverable, underlying cause that can direct therapy more efficiently.