A systematic review of 17 randomized controlled trials of fiber supplements in IBS patients published in 2004 found that SF significantly improved a global IBS symptoms, while IF did not. The results suggest that increasing SF intake for all types of IBS may be beneficial.
I hope this helps - Good luck
Reference Bijkerk, C. J., J. W. M. Muris, J. A. Knottnerus, A. W. Hoes, and N. J. De Wit, 2004: Systematic review: the role of different types of fibre in the treatment of irritable bowel syndrome. Alimentary Pharmacology & Therapeutics Alimentary Pharmacology & Therapeutics, 19, 245-251
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