Complications of Diverticulosis Considering how many millions of Americans have diverticulosis, it is remarkable that so few people are affected by complications. Diverticula usually don't cause any symptoms unless they become inflamed or infected. In fact, most people with diverticulosis experience no symptoms at all. However, complications do occur and can be serious. These may include abdominal pain, rectal bleeding, and diverticulitis.
Most diverticular pouches are painless.
But, if you have enough of them, they can cause thickening and narrowing of the sigmoid colon. This results in painful spams in the lower left part of the abdomen. When diverticulosis is far advanced, the lower colon may become narrowed and distorted. When this occurs, there may be thin or pellet-shaped stools, persistent bouts of constipation, and an occasional rush of diarrhea. Rectal Bleeding Bleeding occurs from a ruptured blood vessel in one of the pouches.