As your doctor said, it is most probably due to constipation, hard big stools in the lower part of your large intestines. Drink lots of water, eat green leafy vegetables for soft, regular bowel movements. Some times a laxative may be required for chronic cases. For diagnosing diverticulosis, Ultrasound of abdomen or an endoscopy may be required. Can you reply with some more information like- -Have you had good bowel movements recently? and How was the consistency-soft, mucoid, hard? -Are you also passing more gas than usual? -Is there any difference in your eating habits recently? -What was the medicine given to you by your doctor? Hope this answers your question. Please reply with above information so that I can help you better