Telephone Brand Sat-Isabgol is a natural, soluble fiber derived from the husks of Isabgol seeds. It is prescribed even by doctors to prevent constipation or to regulate bowel habits in patients with irritable bowel syndrome, diverticular disease, or hemorrhoids. Nature's highest soluble fiber. THE FINEST HUSK IN THE WORLD. Best Brand for the product. Helps Relieve Constipation. Helps Reduce Cholesterol.