Blond psyllium (Plantago ovata), commonly known as psyllium husk, is supported by scientific evidence for use in managing symptoms of Irritable Bowel Syndrome (IBS), particularly IBS with constipation (IBS-C). Multiple randomized controlled trials and meta-analyses have demonstrated that soluble fiber supplementation, such as psyllium, can improve overall IBS symptoms, stool frequency, and stool consistency. Psyllium is a soluble, fermentable fiber that absorbs water and forms a gel-like substance, softening stools and promoting regular bowel movements. This mechanism helps alleviate both constipation and, to a lesser extent, diarrhea by normalizing bowel function.

Clinical guidelines, including those from the American College of Gastroenterology and the British Society of Gastroenterology, recommend soluble fiber like psyllium as a first-line therapy for IBS, especially for constipation-predominant cases. Psyllium is generally better tolerated and more effective than insoluble fibers, such as bran, which can worsen symptoms in some IBS patients. However, the benefit is less pronounced for IBS with predominant diarrhea (IBS-D).

Adverse effects are typically mild, including bloating and gas, especially when starting therapy. Gradual dose escalation can minimize these effects. Overall, scientific evidence supports the use of blond psyllium as an effective and safe adjunctive treatment for IBS, particularly for improving bowel regularity and reducing severity of symptoms.