Irritable bowel syndrome

Overview

Irritable bowel syndrome is the most common disorder of gut–brain interaction. Global epidemiology places IBS prevalence at about 8.5% of adults, within an overall disorders-of-gut-brain-interaction burden above 40%.^[17] It consumes consultations, generates unnecessary investigations, and accumulates iatrogenic harm from reflexive colonoscopy and unsupervised elimination diets.

The conceptual shift that matters for fellowship practice is from exclusion to affirmation. Rome IV reframed these conditions as disorders of gut–brain interaction diagnosed positively on clinical criteria supported by a deliberately narrow test set. The GP's task is to diagnose confidently, subtype accurately, treat by subtype, and keep the red-flag radar running at every review.^[1][18]

References19ShowHide

1. [1]Drossman DA, Hasler WL Rome IV-Functional GI Disorders: Disorders of Gut-Brain Interaction. Gastroenterology, 2016.PMID 27147121
2. [2]Menees SB, Powell C, Kurlander J et al. A meta-analysis of the utility of C-reactive protein, erythrocyte sedimentation rate, fecal calprotectin, and fecal lactoferrin to exclude inflammatory bowel disease in adults with IBS. The American journal of gastroenterology, 2015.PMID 25732419
3. [3]Staudacher HM, Rucco V, Mancell S et al. Fiber supplementation in irritable bowel syndrome: a systematic review and meta-analysis of randomized controlled trials. Gastroenterology, 2026.PMID 42600900
4. [4]Black CJ, Yuan Y, Selinger CP et al. Efficacy of soluble fibre, antispasmodic drugs, and gut-brain neuromodulators in irritable bowel syndrome: a systematic review and network meta-analysis. The lancet. Gastroenterology & hepatology, 2020.PMID 31859183
5. [5]Khasawneh M, Mokhtare M, Moayyedi P et al. Efficacy of gut-brain neuromodulators in irritable bowel syndrome: an updated systematic review and meta-analysis. The lancet. Gastroenterology & hepatology, 2025.PMID 40258375
6. [6]Ford AC, Wright-Hughes A, Alderson SL et al. Amitriptyline at Low-Dose and Titrated for Irritable Bowel Syndrome as Second-Line Treatment in primary care (ATLANTIS): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet (London, England), 2023.PMID 37858323
7. [7]Pimentel M, Lembo A, Chey WD et al. Rifaximin therapy for patients with irritable bowel syndrome without constipation. The New England journal of medicine, 2011.PMID 21208106
8. [8]Rao S, Lembo AJ, Shiff SJ et al. A 12-week, randomized, controlled trial with a 4-week randomized withdrawal period to evaluate the efficacy and safety of linaclotide in irritable bowel syndrome with constipation. The American journal of gastroenterology, 2012.PMID 22986440
9. [9]Chey WD, Lembo AJ, Lavins BJ et al. Linaclotide for irritable bowel syndrome with constipation: a 26-week, randomized, double-blind, placebo-controlled trial to evaluate efficacy and safety. The American journal of gastroenterology, 2012.PMID 22986437
10. [10]Halmos EP, Power VA, Shepherd SJ et al. A diet low in FODMAPs reduces symptoms of irritable bowel syndrome. Gastroenterology, 2014.PMID 24076059
11. [11]O'Brien L, Kasti A, Halmos EP et al. Evolution, adaptation, and new applications of the FODMAP diet. JGH open : an open access journal of gastroenterology and hepatology, 2024.PMID 38770353
12. [12]Wallén H, Lindfors P, Andersson E et al. Return on investment of internet delivered exposure therapy for irritable bowel syndrome: a randomized controlled trial. BMC gastroenterology, 2021.PMID 34256715
13. [13]Daniluk J, Malecka-Wojciesko E, Skrzydlo-Radomanska B et al. The Efficacy of Mebeverine in the Treatment of Irritable Bowel Syndrome-A Systematic Review. Journal of clinical medicine, 2022.PMID 35207315
14. [14]Scaciota ACL, Matos D, Rosa MMB et al. INTERVENTIONS FOR THE TREATMENT OF IRRITABLE BOWEL SYNDROME: A REVIEW OF COCHRANE SYSTEMATIC REVIEWS. Arquivos de gastroenterologia, 2021.PMID 33909790
15. [15]Chang L, Sultan S, Lembo A et al. AGA Clinical Practice Guideline on the Pharmacological Management of Irritable Bowel Syndrome With Constipation. Gastroenterology, 2022.PMID 35738724
16. [16]Dilmaghani S, BouSaba J, Lupianez-Merly C et al. Meta-Analysis: Efficacy and Safety of Sequestrants for Bile Acid Diarrhoea. Alimentary pharmacology & therapeutics, 2025.PMID 41090475
17. [17]Sperber AD, Hreinsson JP, Simrén M et al. Rome V global epidemiology and validation survey: prevalence of disorders of gut-brain interaction and comparison with the Rome IV global epidemiology study. Gut, 2026.PMID 42613194
18. [18]Dalrymple J, Bullock I Diagnosis and management of irritable bowel syndrome in adults in primary care: summary of NICE guidance. BMJ, 2008.PMID 18325967
19. [19]Lindfors P, Axelsson E, Engstrand K, et al. Online Education Is Non-Inferior to Group Education for Irritable Bowel Syndrome: A Randomized Trial and Patient Preference Study. Clinical gastroenterology and hepatology, 2021.PMID 32289541