Executive summary
- Diverticulitis is usually LLQ pain/tenderness ± fever/raised CRP.
- Antibiotics are not automatic for every mild uncomplicated case; reserve for systemic illness/high-risk/worsening symptoms per local guidance.
- Complicated disease (abscess/perforation/obstruction) → urgent imaging/admission.
Assessment and red flags
- Check obs, abdominal exam; pregnancy test where relevant; consider urinalysis (UTI mimic).
- Red flags/admit: peritonism, sepsis, persistent vomiting/inability to tolerate fluids, uncontrolled pain, immunosuppression/frailty, suspected abscess/perforation.
Antibiotics (when indicated)
- First-line: co-amoxiclav 500/125 mg TDS for 5 days.
- If penicillin allergy/unsuitable: follow local antimicrobial guidance; CKS lists combinations such as cefalexin + metronidazole, trimethoprim + metronidazole, or ciprofloxacin + metronidazole (fluoroquinolone cautions apply).
- Review within 48 hours (sooner if deteriorating).
Follow-up and referral
- Supportive care: analgesia, hydration, dietary advice as tolerated; address constipation after recovery.
- Refer/admit if worsening, no improvement, or diagnostic uncertainty; consider colorectal pathways if ongoing bleeding, IDA, weight loss, or persistent change in bowel habit.
Frequently asked questions
Can diverticular disease cause rectal bleeding?
Yes—diverticulosis can cause significant painless bleeding. Assess severity and refer urgently if unstable.
When is it “complicated”?
Sepsis, peritonism, failure to improve, or suspicion of abscess/perforation/obstruction should prompt urgent imaging/admission.
Transparency
This page is an educational, clinician-written summary of publicly available NICE guidance intended for trained healthcare professionals. It uses original wording (not copied text) and should be used alongside the full NICE source, local pathways, and clinical judgement. Doses provided are for general reference; always check the BNF/SPC.