With proper treatment and a high-fiber diet, the outlook for people with diverticulosis and uncomplicated diverticulitis is excellent. Most people with diverticulosis never have symptoms. People who are hospitalized for diverticulitis, usually improve within two to four days after treatment begins. Over 85% of patients recover with bed rest, liquid diet and antibiotics, and most never have a second episode of diverticulitis. The prognosis varies if complications develop and is particularly serious in the case of peritonitis. About 90% of people who have a colon resection do not have symptoms return after the surgery.