Irritable Bowel Syndrome

Zheping Quan et al. (2026) · Frontiers in immunology

This systematic review and network meta-analysis of 16 randomized controlled trials (943 participants) explored which forms of exercise are linked to better outcomes in irritable bowel syndrome (IBS). IBS is a functional gut disorder, meaning the bowel looks normal on testing but causes recurring abdominal pain and altered bowel habits, and it often occurs alongside anxiety and depression. The authors framed the gut and brain as communicating through the brain-gut axis, with the immune system, intestinal barrier and gut microbiota also involved. A network meta-analysis is a statistical method that compares several treatments at once, even when some were never tested head to head, and ranks them using SUCRA, a percentage score where higher values mean a greater chance of being best. The included trials, published between 2004 and 2025, tested yoga, Pilates, Baduanjin (a traditional Chinese gentle movement routine), running and moderate-intensity aerobic exercise for 4 to 24 weeks. Participants were adults with constipation-predominant, diarrhea-predominant or mixed IBS, mostly in Asia, Europe and North America. Comparison groups received conventional treatment, dietary advice, probiotics or education. Researchers measured symptom severity with the IBS Symptom Severity Scale, quality of life with the IBS Quality of Life scale, and mood with anxiety and depression scores. Exercise improved several outcomes. Depression scores fell overall (SMD -0.56, a moderate-sized benefit), though heterogeneity was very high (I2 = 95%, meaning results varied widely between trials), and yoga alone was not significant. Anxiety dropped with yoga (SMD -1.82), Pilates (SMD -3.84) and aerobic exercise (SMD -6.31). Symptom severity improved with running (MD -72.68 points), Pilates (-71.32), aerobic exercise (-46.50) and Baduanjin (-16.94), with running ranked first (SUCRA 90.3%). Quality of life ranked Baduanjin first (99.9%) and yoga second (80.1%), while aerobic exercise showed no significant difference from conventional treatment. In subscale analyses, Pilates cut pain severity (MD -17.90) and aerobic exercise improved dysphoria, activity interference, body image, health worries and relationships, while yoga helped only bowel satisfaction and interference with life. Rankings differed by outcome, which the authors describe as functional specificity. The authors describe exercise as a safe, low-cost non-pharmacological option that may hold value in comprehensive IBS management, but the evidence carries clear limits. Heterogeneity was high, many trials did not clearly blind participants or assessors, and some effect sizes were unusually large, which the authors attribute to small samples. Study counts were reported inconsistently across sections, and safety was not analysed. Too few trials came from outside East Asia to judge differences across ethnic groups. The immune mechanisms remain unproven, and the authors call for trials that add immune markers, biomarkers and gut microbiome measures.

Ilse N Ganzevoort et al. (2026) · The British journal of general practice : the journal of the Royal College of General Practitioners

This randomised controlled trial with 152 Dutch children explored whether home-based guided hypnotherapy, added to usual care from a general practitioner (GP), helps children with functional abdominal pain (recurring stomach pain with no underlying disease found) or irritable bowel syndrome (IBS, abdominal pain linked to bowel habit changes). Both conditions are disorders of gut-brain interaction, meaning the gut and the nervous system influence one another, and in children they are linked with anxiety, school absence and lower quality of life. Hypnotherapy is a state of focused attention in which therapeutic suggestions are used to influence sensation, emotion and thought. It is already available in secondary care, but its effect in primary care had not been tested. Children aged 7 to 17 with a GP diagnosis were randomly assigned to usual care alone (education, reassurance and symptom monitoring) or usual care plus hypnotherapy. Of the 152 children, 46 came through GPs and 106 through social media; median age was 9.4 years. The hypnotherapy group listened to five audio exercises on a website, one for breathing and relaxation and four visualisation exercises, for 15 to 20 minutes on at least five days a week for three months. The main outcome was adequate relief of abdominal pain at 12 months; pain severity was rated from 0 to 10. At 12 months the main result was not statistically significant: 79.5% of the hypnotherapy group reported adequate relief versus 74.3% of the usual care group (adjusted odds ratio 1.47, 90% confidence interval 0.74 to 2.93; the interval includes no difference). Earlier, differences were larger. At 3 months 73.2% versus 56.8% reported relief (odds ratio 2.74, meaning higher odds of relief), and at 6 months 77.6% versus 58.6% (odds ratio 4.26). Pain severity scores were lower in the hypnotherapy group by 1.38 points at 6 months and 0.89 points at 12 months, but not significantly at 3 months. Pain threat beliefs were lower and more children fell asleep within 20 minutes. Anxiety, depression, quality of life and school absence were similar between groups. No adverse events were spontaneously reported, but children were not asked about them directly. The authors suggest that hypnotherapy added to usual care may bring earlier relief and lower pain at low cost, and note that relief at 12 months was high in both groups. The trial had limits: it recruited fewer children than planned, so the significance threshold was relaxed to 10%, which raises the chance of false positives. Participants and clinicians knew who received hypnotherapy, and most families preferred it, so placebo effects are possible. More than 40% of pain diary data were missing. The authors call for research on which children benefit most and on possible adverse effects.

Varol Tunali et al. (2026) · Gut microbes

This 12-month follow-up study revisited 121 adults with irritable bowel syndrome (IBS, a common gut condition causing pain, bloating, and altered bowel habits) who had completed a 6-week randomized trial comparing two dietary approaches: a standard low-FODMAP diet (LFD, which restricts fermentable carbs known to trigger IBS symptoms) and a microbiome-guided personalized diet (PD, built from each person's own gut-bacteria profile using a machine-learning algorithm). The goal was to see whether the benefits people got in the first 6 weeks actually lasted a full year, and whether either diet changed the gut microbiome (the community of bacteria living in the digestive tract) over that time. Participants, recruited at four Turkish gastroenterology clinics, were followed with symptom, quality-of-life, and mood questionnaires plus stool samples for gut-bacteria testing at 6 and 12 months after their original 6-week diet ended (nobody's diet plan was updated again after the start). Seventy people who got the personalized diet and 51 who got the low-FODMAP diet were included at the start of follow-up, though many dropped out over the year, leaving 40 and 29, respectively, providing data at 12 months. Both diets worked well at first, cutting symptom-severity scores by roughly 100 points within 6 weeks. But by 12 months the picture diverged: people on the personalized diet kept most of that improvement (still about 78 points better than baseline), while people on the low-FODMAP diet had drifted back close to where they started. About 63% of the personalized-diet group still counted as meaningful responders at 12 months, compared with about 35% of the low-FODMAP group. The personalized-diet group also showed steadier gains in quality of life and in anxiety and depression scores. On the microbiome side, gut-bacteria diversity rose more and stayed higher in the personalized-diet group throughout the year, though the two groups' overall bacterial makeup looked similar by 12 months, and no single type of bacteria reliably separated the two diets. The takeaway is that tailoring a diet to someone's own gut bacteria may help IBS relief last longer than a standard restrictive diet, which seemed to lose its effect without further guidance. That said, the researchers are careful to call these findings hypothesis-generating rather than proven: many participants dropped out, everyone knew which diet they were on, and the gut-bacteria testing used here cannot show which bacterial genes or byproducts, if any, actually drove the improvement. Larger, purpose-built trials are needed before personalized, microbiome-guided diets become a routine part of IBS care.