Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder characterized by abdominal pain, bloating, and bowel habit abnormalities. PubMed and CINAHL were searched to find randomized clinical trials exploring the efficacy of oral probiotics in relieving IBS symptoms. Five studies found that supplementing Bifidobacterium and lactic acid bacteria significantly reduced abdominal pain and consistently reduced other IBS symptoms at various time points. These studies demonstrated that probiotic supplementation could improve overall IBS symptomology in adults with IBS in as short as 4 weeks.
Lin et al. (Mon,) studied this question.