Many people have small pouches in their colons that bulge outward through weak spots, like an inner tube that pokes through weak places in a tire. Each pouch is called a diverticulum. The condition of having diverticula is called diverticulosis.
When the pouches become infected or inflamed, the condition is called diverticulitis.
The most common symptom of diverticulitis is abdominal pain. If a severe infection is the cause, fever, nausea, vomiting, chills, cramping, and constipation may occur as well. The severity of symptoms depends on the extent of the infection and complications.