Despite years of advising patients to alter their dietary and supplementary fiber intake, the evidence surrounding the use of fiber for functional bowel disease is limited. This paper outlines the organization of fiber types and highlights the importance of assessing the fermentation characteristics of each fiber type when choosing a suitable strategy for patients. Fiber undergoes partial or total fermentation in the distal small bowel and colon leading to the production of short-chain fatty acids and gas, thereby affecting gastrointestinal function and sensation. When fiber is recommended for functional bowel disease, use of a soluble supplement such as ispaghula/psyllium is best supported by the available evidence. Even when used judiciously, fiber can exacerbate abdominal distension, flatulence, constipation, and diarrhea.
1 Division of Gastroenterology, University of Michigan Health System, Ann Arbor, Michigan, USA
2 Monash University, Melbourne, Victoria, Australia
Correspondence: William D. Chey, MD, AGAF, FACG, FACP, Division of Gastroenterology, University of Michigan Health System, 3912 Taubman Center, SPC 5362, Ann Arbor, Michigan 48109-5362, USA. E-mail: email@example.com
Received 17 December 2012; accepted 11 February 2013
published online 2 April 2013