Diverticulosis

I am now a 77 year old male who used to have 2-3 severe events of internal bleeding a year -- defecating red blood which pool collected in the rectum over 20-30 minute intervals -- even to the point of blood loss needing a blood transfusion . Frequent procto exams plus a radiologic method of locating source of bleeding failed to reveal where it was coming from ( no ulcers , no malignancies , no haemorrhoids ) & a diagnosis of diverticulosis was made . About 3 years ago I started taking up to 2 tbspn/day of stool softener / bulker like Metamucil ( psyllium husk ) & have never had another reoccurence of such bleeding . I told my internist but he was non plussed & had no explanation for why it would work so well . Any explanation by a reader would be appreciated -- preferably a medical opinion . Maybe this could be an equivalent to the OZ Dr discovery of B. pylori in stomach ulcer causation for an enterprising physician ?