---
title: "Diverticulitis: Symptoms, Causes & Treatment | HealthAnswers"
description: "Diverticulitis — inflamed pouches in the colon causing abdominal pain, fever, and treatment with antibiotics or surgery."
url: https://healthanswers.co.uk/conditions/diverticulitis/
robots: noindex
---

# Diverticulitis: Symptoms, Causes & Treatment | HealthAnswers

Health A–Z

Diverticulitis — inflamed pouches in the colon causing abdominal pain, fever, and treatment with antibiotics or surgery.

Written by HealthAnswers editorial team Medically reviewed by [HealthAnswers UK doctor review panel](https://healthanswers.co.uk/our-doctors/) Reviewed 3 July 2026

## Quick answer

What is diverticulitis? Diverticulitis is inflammation or infection of diverticula — small pouches that form in the colon wall, common over age 40. Symptoms include constant lower left abdominal pain, fever, and change in bowel habit. Mild cases treated with antibiotics at home; severe cases need hospital admission. High-fibre diet helps prevent diverticular disease. Seek urgent help for severe pain, vomiting, or inability to pass wind — possible perforation or abscess.

## Who is this page for?

This page is for people in the UK who want a plain-English overview of Diverticulitis, including when to seek help and what NHS care usually involves. It explains general information, not what is wrong with you personally.

## Who should skip this page?

Skip this page if you need a diagnosis, a prescription, or emergency care. It cannot replace a GP, pharmacist, NHS 111 or 999. If you are in immediate danger, call 999; for urgent advice that is not life-threatening, call 111 in England, Scotland or Wales, or use your GP out-of-hours service in Northern Ireland.

On this page 7 sections

## Key facts about diverticulitis

- Diverticulosis — having pouches — affects half of people over 60; most never cause problems.
- Diverticulitis — inflamed/infected pouches — pain usually left lower abdomen in Western countries.
- First episode often treated with antibiotics and clear fluids — hospital if unable to tolerate oral intake or sepsis signs.
- Complicated diverticulitis — abscess, perforation, fistula — may need drainage or surgery.
- Nuts and seeds do not cause diverticulitis — outdated advice; fibre is encouraged when well.

## Diverticulitis — when colon pouches flare

**Diverticulosis** — **presence of diverticula** (outpouchings of colon mucosa through muscle wall) — **very common** — **50%** over 60 on colonoscopy.

**Diverticulitis** — **inflammation ± infection** of diverticula — **painful**, **febrile illness** — **5%** with diverticulosis experience this.

## Diverticulosis vs diverticulitis

| | Diverticulosis | Diverticulitis |
| --- | --- | --- |
| Symptoms | Usually none | Pain, fever, malaise |
| Treatment | High fibre prevention | Antibiotics, sometimes surgery |
| Bleeding | Painless PR bleed possible | Less common |

## Symptoms of diverticulitis

**Uncomplicated:**

- constant LLQ pain — left lower abdomen ( sigmoid colon — Western pattern; right-sided in Asia)

- fever

- change bowel habit — constipation or diarrhoea

- nausea

- tenderness — guarding if severe

**Complicated:**

- abscess — persistent fever, mass

- perforation — peritonitis — rigid abdomen — A&E

- fistula — colovesical (pneumaturia), colovaginal

- stricture , obstruction

## Diagnosis

**Clinical** + **CT abdomen/pelvis with contrast** — **gold standard** — shows **wall thickening**, **fat stranding**, **abscess**

**Blood tests** — **CRP**, **WCC** elevated

**Colonoscopy** — **not during acute attack** — **6 weeks post-recovery** if first episode age >40 — **exclude cancer**

## Treatment

### Uncomplicated — outpatient

**Antibiotics covering gut flora:**

- co-amoxiclav

- OR ciprofloxacin + metronidazole (if penicillin allergy — local guidance)

**Clear liquids** → **low residue** briefly → **gradual fibre increase**

**Paracetamol** — **avoid NSAIDs** early — bleeding risk debate

**Some mild cases** — **antibiotics optional** in selected Hinchey 0 — specialist trend — still GP-guided

### Complicated — inpatient

- IV antibiotics

- CT-guided drainage — abscess >3cm often

- surgery — Hartmann’s or resection — perforation, failed medical, recurrent

## Prevention after recovery

- high-fibre diet — 30g/day target

- hydration

- exercise

- healthy weight

- ** nuts/seeds OK ** — myth busted

## Diverticulitis vs other causes

| Condition | Clue |
| --- | --- |
| Appendicitis | RLQ — younger |
| IBS | Chronic pain, no fever |
| Bowel cancer | Weight loss, PR bleed — colonoscopy |
| UTI | Urinary symptoms — colovesical fistula rare |

See [bowel cancer](https://healthanswers.co.uk/conditions/bowel-cancer/) if alarm features.

**Left lower pain + fever over 40** — **same-day assessment** — **CT confirms** — **most home antibiotics**, **some need surgery**.

## ! When to see a GP about diverticulitis

See a GP same day for persistent lower abdominal pain with fever or change in bowel habit — especially over 40. Go to A&E for severe pain, rigid abdomen, vomiting, inability to pass wind, or feeling very unwell — possible perforation. After recovery, discuss fibre intake and colonoscopy timing to exclude cancer mimics.

## Common questions about diverticulitis

What are the symptoms of diverticulitis? Constant abdominal pain — usually left lower quadrant, fever, nausea, constipation or diarrhoea, bloating, blood in stool sometimes. Pain worsens with movement. Unlike diverticulosis which is silent, diverticulitis is painful and systemic illness. What causes diverticular disease? Low-fibre Western diet increases colon pressure causing pouches (diverticulosis) in weak spots of colon wall. Faecal matter trapping in pouches can cause inflammation and bacterial infection (diverticulitis). Age, obesity, smoking, and inactivity increase risk. How is diverticulitis treated? Uncomplicated — oral antibiotics (co-amoxiclav or ciprofloxacin + metronidazole), paracetamol not NSAIDs initially, clear fluids progressing to low fibre then high fibre after recovery. Complicated — hospital IV antibiotics, CT scan, abscess drainage, surgery if perforated or recurrent severe episodes. Should I avoid nuts and seeds with diverticular disease? No — old advice disproven. Nuts, seeds, and popcorn do not cause diverticulitis. When recovered, high-fibre diet reduces recurrence risk. During acute attack, temporary low-fibre diet as advised. Does diverticulitis lead to colon cancer? Diverticular disease does not cause cancer but symptoms overlap — colonoscopy recommended after first episode in age-appropriate patients or if alarm features — to exclude malignancy. Repeated episodes may lower threshold for colonoscopy.

## Sources

- [NHS — Diverticular disease and diverticulitis](https://www.nhs.uk/conditions/diverticular-disease-and-diverticulitis/)
- [NICE — Diverticular disease](https://www.nice.org.uk/guidance/ng147)