Microbiota-directed therapies
Patients with IBS have significant differences in their microbiota compared with people without IBS, but it is unclear whether this represents cause or effect.[103]El-Salhy M, Mazzawi T. Fecal microbiota transplantation for managing irritable bowel syndrome. Expert Rev Gastroenterol Hepatol. 2018 May;12(5):439-45.
http://www.ncbi.nlm.nih.gov/pubmed/29493330?tool=bestpractice.com
[104]Jeffery IB, Das A, O'Herlihy E, et al. Differences in fecal microbiomes and metabolomes of people with vs without irritable bowel syndrome and bile acid malabsorption. Gastroenterology. 2020 Mar;158(4):1016-28.e8.
https://www.gastrojournal.org/article/S0016-5085(19)41920-3/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/31843589?tool=bestpractice.com
[105]Pittayanon R, Lau JT, Yuan Y, et al. Gut microbiota in patients with irritable bowel syndrome-a systematic review. Gastroenterology. 2019 Jul;157(1):97-108.
https://www.gastrojournal.org/article/S0016-5085(19)34649-9/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/30940523?tool=bestpractice.com
Some randomised placebo-controlled trials report an improvement in IBS symptoms in patients receiving faecal microbiota transplantation (FMT), while other studies report no difference in symptom control between the FMT and placebo groups.[106]Aroniadis OC, Brandt LJ, Oneto C, et al. Faecal microbiota transplantation for diarrhoea-predominant irritable bowel syndrome: a double-blind, randomised, placebo-controlled trial. Lancet Gastroenterol Hepatol. 2019 Sep;4(9):675-85.
http://www.ncbi.nlm.nih.gov/pubmed/31326345?tool=bestpractice.com
[107]El-Salhy M, Hatlebakk JG, Gilja OH, et al. Efficacy of faecal microbiota transplantation for patients with irritable bowel syndrome in a randomised, double-blind, placebo-controlled study. Gut. 2020 May;69(5):859-67.
https://www.doi.org/10.1136/gutjnl-2019-319630
http://www.ncbi.nlm.nih.gov/pubmed/31852769?tool=bestpractice.com
[108]Ianiro G, Eusebi LH, Black CJ, et al. Systematic review with meta-analysis: efficacy of faecal microbiota transplantation for the treatment of irritable bowel syndrome. Aliment Pharmacol Ther. 2019 Aug;50(3):240-8.
https://eprints.whiterose.ac.uk/165994
http://www.ncbi.nlm.nih.gov/pubmed/31136009?tool=bestpractice.com
[109]Xu D, Chen VL, Steiner CA, et al. Efficacy of fecal microbiota transplantation in irritable bowel syndrome: a systematic review and meta-analysis. Am J Gastroenterol. 2019 Jul;114(7):1043-50.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7257434
http://www.ncbi.nlm.nih.gov/pubmed/30908299?tool=bestpractice.com
FMT can be successfully accomplished with colonoscopy, use of nasojejunal tubes, or pills.
Ramosetron
Ramosetron, a 5HT-3 receptor antagonist, has been shown to be effective in both men and women for reducing diarrhoea and abdominal pain in diarrhoea-predominant IBS.[110]Qi Q, Zhang Y, Chen F, et al. Ramosetron for the treatment of irritable bowel syndrome with diarrhea: a systematic review and meta-analysis of randomized controlled trials. BMC Gastroenterol. 2018 Jan 8;18(1):5.
https://www.doi.org/10.1186/s12876-017-0734-2
http://www.ncbi.nlm.nih.gov/pubmed/29310568?tool=bestpractice.com
[111]Black CJ, Burr NE, Camilleri M, et al. Efficacy of pharmacological therapies in patients with IBS with diarrhoea or mixed stool pattern: systematic review and network meta-analysis. Gut. 2020 Jan;69(1):74-82.
https://gut.bmj.com/content/69/1/74.long
http://www.ncbi.nlm.nih.gov/pubmed/30996042?tool=bestpractice.com
Constipation is a side effect in around 10% of patients.[112]Fukudo S, Kinoshita Y, Okumura T, et al. Ramosetron reduces symptoms of irritable bowel syndrome with diarrhea and improves quality of life in women. Gastroenterology. 2016 Feb;150(2):358-66.
http://www.gastrojournal.org/article/S0016-5085(15)01584-X/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/26551550?tool=bestpractice.com
It is approved for the treatment of IBS with diarrhoea in several countries, including Japan and India, but not in the US or Europe.
Ondansetron
Ondansetron, a 5HT-3 receptor antagonist, has long been used as an anti-emetic. One large prospective study demonstrated that it was modestly effective versus placebo for improving diarrhoea and well-being in patients with diarrhoea-predominant IBS.[113]Garsed K, Chernova J, Hastings M, et al. A randomised trial of ondansetron for the treatment of
irritable bowel syndrome with diarrhoea. Gut. 2014 Oct;63(10):1617-25.
http://gut.bmj.com/content/63/10/1617.long
http://www.ncbi.nlm.nih.gov/pubmed/24334242?tool=bestpractice.com