Effect of lowFODMAP diet on gastrointestinal symptoms in patients with irritable bowel syndrome: A systematic review of randomized controlled trials

Irritable bowel syndrome is the most common gastrointestinal functional disorder accompanied by symptoms such as abdominal pain and changes in intestinal habits. Lack of proper biochemical criteria for diagnosis, as well as a lack of proper understanding of the pathophysiology of this disease, complicates diagnosis of this disease and undermines the serious efforts to discover the proper drug for it. The present treatments including medical treatments which are related to some sideeffects such as dyspepsia, heartburn, headache, bradycardia, anorexia, weakness and fatigue and diet therapy. The aim of this study was to summarize the results of previous studies on the effect of lowFODMAP diet on the improvement of digestive symptoms and nutritional status in patients with IBS. Electronic literature searches were conducted on PubMed, Web of Science and Google Scholar until May 2019. The search was conducted with the following words “FODMAP” or “lowFODMAP diets”, in combination with “gastrointestinal symptoms”, “diarrhea”, “constipation”, “dyspepsia”, “bloating”, “burp”, “heart burn”, “nausea” and “intestinal cramp” among randomized clinical trials. Our search was supplemented with the search of publisher databases Elsevier, Wiley Online and SpringerLink and for any pertinent studies, we screened the references of all included studies. Eligibility criteria included: randomized controlled clinical trial studies published in peerreviewed journals and studies that used lowFODMAP diets as an intervention. In the total of 5 studies were done on the 299 adults who meet the inclusion criteria. According to the consumption of the results, the lowFODMAP diet caused a significant improvement in many gastrointestinal symptoms, such as abdominal pain, bloating, diarrhea, constipation, and dissatisfaction of the intestinal habits in comparison with control diet. According to the results of various studies, it seems that a lowFODMAP diet can improve digestive symptoms and IBSrelated complaints.