Assessment of diverticulitis

Diverticulitis occurs when a colonic diverticulum becomes inflamed. Diverticulitis usually presents with abdominal pain in the left lower quadrant and fever, often with an altered bowel habit. Consider alternative diagnoses (eg irritable bowel syndrome, colonic malignancy). Consider abdominal imaging such as abdominal computed tomography (CT) or ultrasound, because a diagnosis of diverticulitis made by clinical criteria alone is often incorrect. See also Assessment of intra-abdominal infections.

Diverticulitis ranges in severity from subclinical local inflammation to generalised peritonitis following perforation. Complicated (severe) diverticulitis refers to diverticulitis with any of:

• a positive blood culture result
• perforation
• peritonitis
• sepsis or septic shock
• an abscess larger than 5 cm in diameter.

Diverticulitis without any of these features is considered uncomplicated (nonsevere) and accounts for the majority of cases.

Screening for colorectal cancer is recommended 6 to 8 weeks after an acute episode of diverticulitis, for all patients with complicated diverticulitis and some patients with uncomplicated diverticulitis – see Colorectal cancer screening in patients with diverticular disease after an acute diverticulitis episode.

See also Diverticulosis for prevention of diverticulitis, and Diverticular bleeding.