The soluble fiber found in psyllium husks can help lower cholesterol. Psyllium can help relieve both constipation and diarrhea, and is used to treat irritable bowel syndrome, hemorrhoids, and other intestinal problems. Psyllium has also been used to help regulate blood sugar levels in people with diabetes.verview. Psyllium is a soluble fiber used primarily as a gentle bulk-forming laxative in products such as Metamucil. It comes from a shrub-like herb called Plantago ovata that grows worldwide but is most common in India.