Diverticulitis: the unknown 'bags' that appear in the intestine. Diverticula are small pouches, a kind of bulging sac that form on the inner wall of the intestine, mainly in the large intestine.
Nobody knows exactly why these bags appear. One hypothesis could be a low-fiber diet that results in constipation and hard stools. It is estimated that colonic diverticula appear in one in five people in general, with 70% in those over 80 years of age.