Psyllium is a soluble fiber derived from the husks of Plantago ovata seeds and is widely recognized for its role in digestive health, particularly as a bulk-forming laxative. Its primary use in patients with a prolapsed colon (also known as rectal prolapse) is to support bowel regularity and ease defecation, thereby potentially reducing straining during bowel movements—an important consideration in managing this condition. Straining can exacerbate or worsen prolapse symptoms, so interventions that reduce this are clinically relevant.

Scientific evidence, although not directly targeting rectal prolapse, supports the use of psyllium for improving stool consistency and promoting regularity in cases of chronic constipation and irritable bowel syndrome with constipation (IBS-C). Several clinical trials and meta-analyses demonstrate that psyllium increases stool bulk, softens stool, and makes passage easier, which can help patients with prolapse avoid hard stools and excessive straining. Guidelines from gastroenterological societies often recommend fiber supplementation, including psyllium, as a first-line intervention for constipation, which is frequently associated with rectal prolapse.

However, it is important to note that while psyllium can help manage symptoms and may prevent worsening of prolapse by minimizing straining, it does not treat the structural issue of prolapse itself. Its use is best seen as symptomatic support rather than a curative measure. The overall evidence is moderate (3/5) because most studies focus on constipation rather than prolapse directly, but the rationale for use is well-accepted in clinical practice.