Diverticulite

Diverticulite, commonly referred to as diverticulitis, is inflammation or infection of one or more diverticula in the colon. Diverticulosis denotes the presence of diverticula without inflammation. Diverticulitis is part of the broader spectrum of diverticular disease.

Diverticula are pouch-like herniations of the mucosa through the muscular wall of the colon, often developing where the colonic wall is weakened. The condition is more common in older adults and in Western countries. Risk factors include a low-fiber diet, obesity, smoking, certain medications such as nonsteroidal anti-inflammatory drugs, and lack of physical activity.

Symptoms of acute diverticulitis include localized abdominal pain (typically in the lower left quadrant, but presentation may vary), fever, nausea, and changes in bowel habits. Complications include abscess, perforation, peritonitis, fistula, and bowel obstruction. Diagnosis relies on clinical assessment supported by imaging—computed tomography with contrast is the preferred test in many settings. Blood tests may show elevated white blood cell count and inflammatory markers. Colonoscopy is generally avoided during an acute attack but is used after resolution to identify other diseases or assess the colon.

Treatment depends on severity. Uncomplicated diverticulitis may be treated on an outpatient basis with rest, hydration, and either observation or oral antibiotics targeting gram-negative bacteria and anaerobes; some guidelines support antibiotics, others reserve them for certain patients. Complicated diverticulitis (abscess, perforation, obstruction, or generalized sepsis) typically requires hospital admission, IV antibiotics, and possibly abscess drainage or surgical intervention. Recurrent or complicated disease may require elective surgery.

Most patients recover fully with appropriate treatment. After an episode, individuals are advised to manage risk factors with a high-fiber diet, weight management, and avoidance of smoking where possible. A colon evaluation is often performed after resolution to check for other conditions and to guide future management.