← Issue №7/ week of Aug 16, 2026/Motility

Consolidation Therapy of Probiotics With Rifaximin Prevent Relapse in Rifaximin-Responsive Diarrhea-Predominant Irritable Bowel Syndrome: A Multicenter Randomized Clinical Trial.

From GI Signals issue №7: what this paper found, what it changes, and where it sits against the current standard of care, reviewed by Simon Mathews, MD.

Motility rct · n=143 · Aug 18, 2026 · J Gastro Hep · IF 3.5

Consolidation Therapy of Probiotics With Rifaximin Prevent Relapse in Rifaximin-Responsive Diarrhea-Predominant Irritable Bowel Syndrome: A Multicenter Randomized Clinical Trial.

New therapyIBSmicrobiome
Clinical takeawayIn IBS-D patients responding to rifaximin, consolidation with 4 weeks of Medilac-S (Bacillus subtilis and Enterococcus faecium) may be considered to reduce relapse risk. Clinicians should note this contradicts current ACG recommendations against probiotics in IBS (conditional, very low evidence against).
What it foundIn IBS-D patients responding to rifaximin, 4-week Medilac-S consolidation therapy reduced relapse from 58% to 40% (p=0.0378) and improved bowel frequency (1.73 vs 2.53 stools/day, p<0.001) and stool consistency (BSFS 4.38 vs 5.15, p<0.001).
ContextRifaximin achieves good initial remission but relapse remains common. This open-label multicenter RCT tested post-rifaximin probiotic consolidation in a specific population (rifaximin-responders). While the 18-point relapse reduction is clinically meaningful, the open-label design and borderline significance (p=0.0378) mean this single trial does not overturn guideline guidance; should involve shared decision-making and explicit discussion that this is an off-guideline approach.
Refinessuggested applicable standard· American College of Gastroenterology, 'ACG Clinical Guideline: Management of Irritable Bowel Syndrome', 2021

Decision at stakewhether to recommend probiotics in IBS-D management

IBS-D: rifaximin (strong, moderate); alosetron only for women with severe IBS-D who have failed conventional therapy (conditional, low); mixed opioid agonists/antagonists, i.e. eluxadoline (conditional, moderate); AGAINST bile acid sequestrants (conditional, very low).

From our summary of this standard, unedited — the part the paper bears on. marks omitted text. Our wording, not the guideline's; read the source for its own text. The rest of this standard includes IBS-C.

Our full summary of this standard

Diagnosis: use a positive diagnostic strategy based on Rome IV criteria rather than a strategy of exclusion (strong for cost-effectiveness, high quality; consensus for time-to-therapy), and categorize by IBS subtype (consensus). In patients with IBS and diarrhea symptoms: check celiac serology (strong, moderate) and, in those WITHOUT alarm features, fecal calprotectin (or fecal lactoferrin) plus CRP to rule out IBD (strong; moderate quality for CRP/calprotectin, very low for lactoferrin). Recommend AGAINST routine stool testing for enteric pathogens (conditional, low) and AGAINST routine colonoscopy in patients younger than 45 without warning signs (conditional, low). Anorectal physiology testing only when symptoms suggest a pelvic floor disorder and/or for refractory constipation not responding to standard medical therapy (consensus). Treatment, all subtypes: soluble, not insoluble, fiber (strong, moderate); a LIMITED trial of a low-FODMAP diet (conditional, very low); gut-directed psychotherapies for global symptoms (conditional, very low); TCAs for global symptoms (strong, moderate); peppermint suggested (conditional, low); antispasmodics for abdominal pain (conditional, low); AGAINST probiotics (conditional, very low), AGAINST fecal transplant (strong, very low). IBS-C: chloride channel activators (strong, moderate) and guanylate cyclase activators (strong, high); AGAINST PEG products for global IBS-C symptoms (conditional, low); tegaserod reserved for women younger than 65 with ≤1 cardiovascular risk factor who have not adequately responded to secretagogues (strong/conditional, low). IBS-D: rifaximin (strong, moderate); alosetron only for women with severe IBS-D who have failed conventional therapy (conditional, low); mixed opioid agonists/antagonists, i.e. eluxadoline (conditional, moderate); AGAINST bile acid sequestrants (conditional, very low).

American College of Gastroenterology, 'ACG Clinical Guideline: Management of Irritable Bowel Syndrome', 2021 · reviewed 2026-07-21 ↗
Zhong J … Wang L · Journal of Gastroenterology and Hepatology · IF 3.5 · PubMed ↗Permalink
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