If the pouches become inflamed or infected, you have a condition called diverticulitis. The most common symptom is abdominal pain, usually on the left side. You may also have fever, nausea, vomiting, chills, cramping, and constipation. In serious cases, diverticulitis can lead to bleeding, tears, or blockages. Your doctor will do a physical exam and imaging tests to diagnose it. Treatment may include antibiotics, pain relievers, and a liquid diet.