Diverticular disease collectively encompasses a spectrum of pathology including diverticulosis and diverticulitis. Particularly in Western populations, it is present in 30% of individuals over 60 years of age and in 60% of those over 80 years of age. Diverticulitis most commonly affects the sigmoid colon (95%) of elderly patients. It is seen equally in males and females. In 35% of patients, the proximal colon is also involved. Risk factors include low-fiber diet, tobacco use and chronic constipation. Typically, these are false (pulsion) diverticula involving herniation of mucosa and muscularis mucosa through the muscularis externa that occur at an area of weakness (near the vasa recta) [1].

Infectious, inflammatory and ischemic etiologies of colonic pathology need to be considered. Additionally, large bowel obstruction from a neoplastic process may occasionally present with similar symptoms. In females, gynecologic pathology (e.g., ruptured ovarian cyst or pelvic inflammatory disease) needs to be considered. In the presence of concomitant urinary complaints, renal colic from nephrolithiasis and pyelonephritis is included in the differential.

Patient presentation could range from asymptomatic state to life-threatening complications of acute intraabdominal sepsis. Uncomplicated disease (occurring in 75–80% of cases) manifests as abdominal pain, fever, leukocytosis and anorexia or obstipation [2]. Complicated disease is associated (by definition) with abscess (Hinchey I and II) or perforation (Hinchey III and IV). More rarely, fistulae and stricture may develop (see below).

Diagnosis is best made using CT scanning, with findings of diverticula along with colonic thickening and inflammation or stranding within the pericolonic fat.

Complications can be categorized as acute (perforation and abscess) or chronic (stricture and fistulae). Perforated diverticulitis that presents with a few smaller pockets of extraluminal air needs to be differentiated from free intraperitoneal air over the liver on CT imaging. The latter needs to be treated emergently with fluid resuscitation, broad-spectrum antibiotics and urgent laparotomy. Classically, a Hartmann procedure (sigmoidectomy with end colostomy) is performed.