title: Systematic review: dietary fibre and FODMAP-restricted diet in the management of constipation and irritable bowel syndrome.
abstract: BACKGROUND
  Dietary fibre supplements have been advocated for the management of chronic constipation (CC) and irritable bowel syndrome (IBS). Recently, a fermentable oligosaccharide, disaccharide, monosaccharide and polyol (FODMAP) restricted diet has been recommended for IBS.
  
  
  OBJECTIVE
  To systematically examine recent evidence for dietary interventions with fibre in CC and IBS and FODMAP-restricted diet in IBS, and provide recommendations.
  
  
  METHODS
  We searched PUBMED, MEDLINE, OVID and COCHRANE databases from 2004 to 2014. Published studies in adults with CC and IBS and constipation-predominant IBS (IBS-C) that compared fibre with placebo/alternative and FODMAP-restricted diet with alternative were included.
  
  
  RESULTS
  Of 550 potentially eligible clinical trials on fibre, 11 studies were found and of 23 potentially eligible studies on FODMAPs, six were found. A meta-analysis was not performed due to heterogeneity and methodological quality. Fibre was beneficial in 5/7 studies in CC and 3/3 studies in IBS-C. FODMAP-restricted diet improved overall IBS symptoms in 4/4 and IBS-C symptoms in 1/3 studies and three studies did not meet inclusion criteria. There were significant disparities in subject selection, interventions and outcome assessments in both fibre and FODMAPs studies.
  
  
  CONCLUSIONS
  Fibre supplementation is beneficial in mild to moderate CC and IBS-C, although larger, more rigorous and long-term RCTs are needed (Fair evidence-Level II, Grade B). Although the FODMAP-restricted diet may be effective in short-term management of selected patients with IBS (Fair evidence-Level II, Grade C) and IBS-C (Poor evidence-Level III, Grade C), more rigorous trials are needed to establish long-term efficacy and safety, particularly on colonic health and microbiome.
authors.affiliation: Section of Gastroenterology/Hepatology, Department of Internal Medicine, Georgia Regents University, Augusta, GA, USA.
authors.forename: S S C
authors.initials: SS
authors.lastname: Rao
authors.affiliation: Section of Gastroenterology/Hepatology, Department of Internal Medicine, Georgia Regents University, Augusta, GA, USA.
authors.forename: S
authors.initials: S
authors.lastname: Yu
authors.affiliation: Food and Nutrition Department, Georgia Regents University, Augusta, GA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Fedewa
mesh_terms: D000328:Adult; D003248:Constipation / Q000628:therapy*; D004035:Diet Therapy / Q000379:methods*; D004043:Dietary Fiber / Q000008:administration & dosage*; D004187:Disaccharides / Q000627:therapeutic use; D019468:Disease Management; D005285:Fermentation; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000628:therapy*; D009005:Monosaccharides / Q000627:therapeutic use; D009844:Oligosaccharides / Q000627:therapeutic use; D011108:Polymers / Q000627:therapeutic use
chemical_list: D004043:Dietary Fiber; D004187:Disaccharides; D009005:Monosaccharides; D009844:Oligosaccharides; D011108:Polymers; C024617:polyol