High-yield map
Key points before the detail
- 01
Diverticulosis, diverticular disease and diverticulitis are different entities.
- 02
CT is the key test when complications are suspected.
- 03
Selected systemically well uncomplicated patients may not need antibiotics.
- 04
NICE advises considering drainage or surgery for abscesses >3 cm.
- 05
Elective surgery is individualised, not triggered by a fixed number of attacks.
1. Define the problem precisely
| Term | Meaning |
|---|---|
| Diverticulosis | Presence of diverticula, usually incidental. |
| Diverticular disease | Symptoms attributed to diverticula without acute inflammation. |
| Acute diverticulitis | Acute inflammation; uncomplicated or complicated. |
| Complicated diverticulitis | Abscess, fistula, obstruction/stricture, perforation or peritonitis. |
| Diverticular bleeding | Often painless arterial lower-GI bleeding. |
2. Investigation
- FBC, CRP, U&E and other severity-dependent bloods.
- Contrast CT abdomen/pelvis in suspected complication or diagnostic uncertainty.
- Avoid colonoscopy during acute diverticulitis.
- After recovery, luminal assessment is individualised by CT quality, age, symptoms, anaemia and cancer suspicion.
3. Practical CT severity
| Stage | Description | Direction |
|---|---|---|
| Ia | Pericolic inflammation/phlegmon or small local gas. | Conservative treatment if stable. |
| Ib | Pericolic/mesocolic abscess. | Antibiotics; drainage decision by size/accessibility/response. |
| II | Distant pelvic/intra-abdominal/retroperitoneal abscess. | IV antibiotics plus drainage when feasible. |
| III | Generalised purulent peritonitis. | Emergency operative source control. |
| IV | Generalised faecal peritonitis. | Emergency resection and source control. |
4. Uncomplicated acute diverticulitis
- Selected systemically well, immunocompetent patients may be managed as outpatients with hydration, analgesia and safety-netting without routine antibiotics.
- Use antibiotics when systemically unwell, immunosuppressed, significantly comorbid or complicated disease is suspected.
- Admit for sepsis, uncontrolled pain, vomiting/dehydration, frailty, immunosuppression or diagnostic uncertainty.
5. Diverticular abscess
| Finding | Management principle |
|---|---|
| <3 cm and stable | Antibiotics with close review and step-down when improving. |
| >3 cm | Consider image-guided drainage or surgery according to size, position, accessibility and physiology. |
| No improvement | Reassess and re-image when it will change drainage/operative planning; secure source control rather than simply prolonging antibiotics. |
6. Perforation, fistula and elective surgery
- Generalised peritonitis requires urgent source control; primary anastomosis versus Hartmann depends on physiology, contamination and bowel quality.
- Colovesical fistula causes recurrent UTI, pneumaturia and faecaluria; define anatomy and exclude malignancy before planned resection.
- Do not schedule elective sigmoid resection solely because of a fixed number of previous attacks; use complications, quality of life, recurrence severity, immune status and patient preference.
Active recall
Close the notes and answer these
Try each question from memory before revealing the answer. These public prompts are a small preview of the integrated retrieval system inside SurgAtlas.
01What distinguishes diverticulosis from diverticulitis?
Diverticulosis is the presence of diverticula; diverticulitis is acute inflammation of a diverticulum and surrounding tissues.
02What is the key imaging test in suspected complicated diverticulitis?
Contrast CT of the abdomen and pelvis.
03Do all uncomplicated cases require antibiotics?
No. Selected systemically well immunocompetent patients can be managed without routine antibiotics.
04At what abscess size does current NICE guidance advise considering drainage or surgery?
Above 3 cm, interpreted with anatomy and clinical condition.
05Does a fixed number of attacks mandate elective sigmoidectomy?
No. Elective surgery is individualised.
Sources & editorial basis
References & editorial basis
- SurgAtlas production source. General Surgery — Diverticular Disease. Public lesson curated from the corresponding production chapter.
- NICE NG147. Diverticular disease: diagnosis and management, including updated antimicrobial recommendations.
This lesson is derived from the corresponding SurgAtlas production teaching material. Where the source makes current management or guideline claims, the public lesson uses the cited contemporary guidance. It is written for education and examination preparation, not as patient-specific clinical advice.
Editorial details
Medical Doctor (MD) · MRCS Part A · Physician · Surgical Educator
SurgAtlas is an educational resource. For patient care, verify current national guidance, local antimicrobial and transfusion policies, specialty pathways and individual patient factors.
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