Complications. The major complication of diverticulosis is that it can turn into diverticulitis. This is when bacteria enter the diverticula and set up an infection. In that case, the person will have tenderness and disabling pain in their abdomen. They may see blood in their stool and suffer from fever and chills as well as nausea and vomiting. Diverticulitis is a serious condition and can lead to perforation of the intestine, peritonitis, which is a inflammation of the abdominal lining, abscesses and fistulas. These problems may require surgery to correct.