Janet21 I was diagnosed with diverticulosis after a colonoscopy. It does not cause symptoms, and was found coincidentally at this examination. Many people over 60 have this condition. It is only when the diverticula become inflamed (diverticulitis) and cause symptoms, including abdominal pain, that they need treatment. Narrow stools are not a symptom. As others have said the stools if soft are shaped by passing through anal sphincter, and bulky hard stools, as MOnica says can be painful as they stretch the sphincter.