Diverticular Disease
Small pouches in the colon wall that can cause symptoms, bleeding or inflammation.
Overview
Diverticula are common — present in over half of adults aged 60+. Most are asymptomatic (diverticulosis). A minority develop symptomatic diverticular disease, diverticular bleeding, or diverticulitis (inflammation/infection).
Symptoms
- • Often asymptomatic, found incidentally
- • Intermittent left lower abdominal pain relieved by defaecation
- • Bloating, altered bowel habit
- • Painless rectal bleeding (diverticular bleed)
- • In diverticulitis: persistent pain, fever, tenderness
Risk factors
- • Age >50
- • Low fibre, high red-meat diet
- • Obesity, smoking, NSAIDs, opioids
- • Sedentary lifestyle
- • Western diet
Causes
- • Increased intraluminal pressure with low-fibre diet
- • Age-related weakening of colonic wall
- • Altered gut microbiota and mucosal inflammation
🚨 Red flags — seek urgent care
- • Severe pain with peritonism — perforation
- • Heavy or persistent bleeding — admit
- • Sepsis features (fever, tachycardia, hypotension)
- • Recurrent diverticulitis with stricture or fistula symptoms
When to seek care
- • Persistent left lower abdominal pain with fever
- • Rectal bleeding (always investigate)
- • Change in bowel habit lasting >6 weeks (exclude colorectal cancer)
Diagnosis
- • CT abdomen for suspected diverticulitis (modified Hinchey grading)
- • Colonoscopy 4–6 weeks after acute episode to exclude malignancy
- • Bloods: FBC, CRP, U&E
- • Differentiate uncomplicated vs complicated (abscess, perforation, fistula)
Treatment
- • Asymptomatic: high-fibre diet, hydration, activity
- • Symptomatic uncomplicated: dietary fibre, antispasmodics, paracetamol; avoid NSAIDs/opioids
- • Acute uncomplicated diverticulitis: often managed without antibiotics in low-risk patients (NICE 2019)
- • Complicated diverticulitis: IV antibiotics, drainage of abscess, surgery if perforation
- • Elective resection in recurrent complicated disease or fistula
Prevention
- • 30 g fibre/day, ≥1.5 L water, regular activity
- • Healthy weight; stop smoking; limit NSAIDs
Complications
- • Abscess, perforation, peritonitis
- • Colovesical or colovaginal fistula
- • Stricture and obstruction
- • Diverticular bleeding
Prognosis
Most diverticulosis remains asymptomatic. Around 75% of diverticulitis resolves with conservative treatment; ~20% recur.
Education & self-care
Fibre, hydration and activity are the foundation. Most diverticular disease is manageable; only a minority ever need surgery.
Frequently asked questions
Should I avoid nuts and seeds?
No — this old advice has been disproved. Nuts and seeds do not increase diverticulitis risk.
Do I need antibiotics for every flare?
No. Uncomplicated diverticulitis in low-risk patients often improves with supportive care alone.
Do I need to avoid nuts and seeds?
No — older advice to avoid nuts, seeds and popcorn is not supported by evidence. A high-fibre diet, hydration and regular activity remain the best preventive measures.
Is surgery ever needed?
Most diverticulitis settles with antibiotics and bowel rest. Surgery is reserved for complications such as abscess, perforation, fistula or recurrent severe episodes.
How likely is it to come back?
About a third of people have a recurrence within 5 years of a first episode. High-fibre diet, regular exercise and not smoking lower the risk.