The ACG 2021 IBS guideline: what it recommends, how it grades, and where the evidence is thin
The first ACG clinical guideline for IBS built with GRADE answers 25 questions. Several of its clearest-sounding recommendations rest on low or very-low-quality evidence. A reader's guide to the grades.
Research, trials, and real accounts on irritable bowel syndrome. Curated, cited, and clearly labeled.
Latest research
New IBS trials and reviews from PubMed, tagged by treatment.
Comparative Effects of Four Dietary Approaches on Symptom Severity and Quality of Life in Irritable Bowel Syndrome: A Randomized Controlled Trial.
Otay Lule N, Yurttagul M, Yildirim AE, et al.
Co-supplementation of zinc and probiotic on oxidative stress markers and sleep quality index in irritable bowel syndrome patients: a double-blind randomized controlled trial.
Rezazadegan M, Saneei P, Soheilipour M, et al.
Systematic Review and Meta-Analysis: Plant-Based Therapy for Irritable Bowel Syndrome.
Meyer A, Auer J, Cascant-Ortolano L, et al.
Study critiques
One study at a time: what it found, what it can and cannot tell you.
The ACG 2021 IBS guideline: what it recommends, how it grades, and where the evidence is thin
The first ACG clinical guideline for IBS built with GRADE answers 25 questions. Several of its clearest-sounding recommendations rest on low or very-low-quality evidence. A reader's guide to the grades.
CBT by telephone or web for refractory IBS: the ACTIB trial and its 24-month follow-up
ACTIB randomised 558 UK patients with refractory IBS to telephone CBT, web CBT, or usual care. Both CBT arms cut symptom severity at 12 months; telephone CBT held up at 24 months, web CBT partly faded.
Faecal microbiota transplantation for IBS: three trials, three different answers
Johnsen (colonoscopic FMT, positive), Halkjær (capsules, placebo won) and El-Salhy (single donor, dose response, 77 to 89% responders) reach opposite conclusions. What the contrast tells us about FMT in IBS.
Recruiting trials
Interventional IBS studies currently enrolling, from ClinicalTrials.gov.
Feasibility Study of a Guided Imagery Therapy Mobile Application for Functional Abdominal Pain Disorders in Children
Guided Imagery Therapy
Study Evaluating the Effect of UCB8600 on Mast Cell Activation in the Human Gut
Sample collection
Defining Objective Markers of Compliance for Dietary Therapies in IBS
Diet A - elimination diet · Diet B - healthy eating diet
Listing only. Eligibility is decided by the study team. TreatIBS is not involved in recruitment.
In the news
Headlines from medical publishers and societies, linked to the original.
Bowel cancer “melted away” after immunotherapy, then stayed away
A short course of immunotherapy before surgery may offer remarkably durable protection for some patients with stage two or three bowel cancer.
Real-time abdominal pain – daily life trigger associations in IBS: a multicenter Experience Sampling Method Study
Gastrointestinal symptoms in irritable bowel syndrome (IBS) are influenced by daily life triggers.
Easing constipation: A 20-minute walk can get your gut moving almost immediately
Researchers found that just 20 minutes of comfortable walking can rapidly stimulate the gut. Within one to two minutes after exercise, bowel sounds became…
Blue Notes
Irritable bowel syndrome (IBS) is associated with sex- and gender-related differences in prevalence and clinical presentation.
Blood tests reveal why astronauts get constipated in space
Spaceflight may dramatically change the gut within weeks, causing bacteria to break down more protein as food moves more slowly through the intestines.
Treatments
Thirteen approaches with guideline positions, studies, trials, and stories in one place.
Diet
Low FODMAP diet
A short restriction of fermentable carbohydrates followed by staged reintroduction; ACG, BSG, and NICE support a supervised trial, with the evidence graded very low quality.
Medications
Rifaximin
A minimally absorbed antibiotic for IBS-D; ACG recommends it (strong, moderate), AGA conditionally suggests it including retreatment, and BSG grades it weak with a limited effect on pain.
Linaclotide, plecanatide, lubiprostone, tenapanor
Prescription drugs for IBS-C that increase fluid in the gut; linaclotide carries strong, high-certainty recommendations from ACG, AGA, and BSG, with the others graded strong or conditional.
Tricyclics and SSRIs (gut-brain neuromodulators)
Low-dose tricyclic antidepressants are recommended for global IBS symptoms by ACG (strong) and BSG (strong), and conditionally by AGA; AGA suggests against SSRIs, while BSG and NICE allow them as a later option.
Eluxadoline
A gut-targeted mixed opioid-receptor drug for IBS-D; ACG, AGA, and BSG all give it a conditional or weak recommendation on moderate evidence, and it is contraindicated after gallbladder removal.
Alosetron and 5-HT3 antagonists
Serotonin 5-HT3 receptor blockers for IBS-D; ACG conditionally recommends alosetron for women with severe symptoms, AGA conditionally suggests it, and BSG rates the class likely the most efficacious for IBS-D.
Supplements
Peppermint oil
An enteric-coated herbal antispasmodic; ACG conditionally suggests it and BSG grades it weak, with pooled trials positive but low in quality and a large 2020 trial missing its primary endpoints.
Soluble fiber (psyllium)
Psyllium (ispaghula) and other soluble fibres are first-line options in ACG, BSG, and NICE guidance, while insoluble bran is discouraged; pooled trials show a modest benefit with a number needed to treat around 7.
Probiotics
Live bacterial supplements with strain-specific and inconsistent trial results; ACG suggests against them for global symptoms, while BSG and NICE allow a time-limited trial without naming a strain.
Mind and gut
Gut-directed hypnotherapy
A structured course of hypnosis focused on gut sensation; ACG conditionally suggests gut-directed psychotherapies, BSG grades it strong on low-quality evidence, and NICE lists it for refractory symptoms.
Cognitive behavioral therapy
IBS-specific CBT targets symptom-related thoughts and behaviours; ACG conditionally suggests gut-directed psychotherapies, BSG grades CBT strong on low-quality evidence, and NICE lists it for refractory symptoms.
Lifestyle
Exercise and physical activity
Regular physical activity is advised for everyone with IBS by BSG (strong, on weak evidence) and NICE; a Swedish trial and small yoga studies suggest symptom benefit, but trials are few and at high risk of bias.
Procedures
Fecal microbiota transplantation
Transfer of processed donor stool into the gut remains investigational for IBS; ACG recommends against it for global symptoms, BSG lists it among treatments in development, and trial results conflict by route and donor.
Stories
Public accounts from people managing IBS, labeled as individual experience.
Alex Robb: six weeks of group CBT for toilet-related fear with IBS
Reported that group CBT with graded exposure changed how he read the urge to go, from needing a toilet immediately to a signal he could wait on, and that he no longer plans his days around toilet access.
Three years into low FODMAP: Becky Excell on what the diet did and did not change
Reported the diet helped her identify specific triggers (garlic, onion, gluten) and improved symptoms partly, then plateaued; she still has symptoms, which she links to stress and to some foods classed as low FODMAP.
Caitlyn Mcadam: IBS-C diagnosed in sixth form, laxatives, a hospital dietitian and yoga
Reported that daily porridge, eating three regular meals slowly, limiting caffeine, takeaways and solid chocolate, and starting evening yoga noticeably reduced her bloating and pain in the month after a bad Christmas; she still turns to laxatives after long stretches without a bowel movement.
A symptom and treatment journal that keeps the evidence next to your notes
Log what you try and how you feel, and see the research for each approach as you go. Join the waitlist to hear when it opens.
Resources
Patient information from NIDDK, IFFGD, Monash University, the Rome Foundation, and the ACG.