Diverticular Disease and Diverticulitis

🧭 When to suspect

Diverticular disease sits on a spectrum, and naming the right point on it drives everything that follows:

• Diverticulosis is the presence of diverticula without symptoms – common with age and usually found incidentally; around 80–85% of affected people stay asymptomatic.

• Diverticular disease is symptomatic diverticula with mild pain or tenderness but no systemic upset.

• Acute diverticulitis is when diverticula become inflamed or infected.

• Complicated disease is diverticulitis with an abscess, perforation, fistula, stricture or sepsis.

Suspect diverticular disease in a person (usually over 50) with:

• Intermittent left lower quadrant (LLQ) pain alongside constipation, diarrhoea or occasional large rectal bleeds – the pain is often triggered by eating and relieved by passing stool or flatus

• LLQ tenderness on examination

Suspect acute diverticulitis when:

• The pain becomes constant and severe in the LLQ with fever

• A sudden change in bowel habit with significant rectal bleeding or mucus

• A tender LLQ mass in someone with known diverticula

Two questions then run through the whole consultation: is the person systemically well, and are there any features of complicated disease?

Be aware symptoms overlap with IBS, colitis and colorectal cancer, and that in a minority – and in people of Asian family origin – pain may localise to the right lower quadrant.

Source: NICE NG147