Last reviewed: 6 Nov 2021
Last updated: 15 Jun 2021

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • left lower quadrant abdominal pain
  • leukocytosis
  • fever
  • rectal bleeding

Other diagnostic factors

  • guarding in left lower quadrant
  • tenderness in left lower quadrant
  • bloating
  • constipation
  • pelvic tenderness on digital rectal examination
  • diffuse abdominal tenderness
  • diarrhoea
  • palpable abdominal mass

Risk factors

  • age >50 years
  • low dietary fibre
  • diet rich in salt, meat, and sugar
  • obesity (BMI >30)
  • non-steroidal anti-inflammatory drug and opioid use

Diagnostic investigations

1st investigations to order

  • FBC with differential
  • urea and electrolytes
  • C-reactive protein

Investigations to consider

  • contrast CT scan of abdomen
  • non-contrast CT scan of abdomen
  • abdominal ultrasound (graded-compression)
  • MRI
  • chest x-ray
  • colonoscopy
  • sigmoidoscopy
  • CT angiogram
  • isotope-labelled red blood cell nuclear scan
  • diagnostic laparoscopy
  • blood culture
  • ABG and serum lactate

Treatment algorithm

Contributors

Expert advisers

Mohamed A. Thaha, PhD, FRCS (Gen Surg), PG Cert Hlt Econ

Senior Lecturer & Lead Consultant in Colorectal Surgery

National Bowel Research Centre

Blizard Institute

Barts and The London School of Medicine and Dentistry

The Royal London Hospital

Queen Mary, University of London

London

UK

Disclosures

MAT declares that he has no competing interests.

Jayan Dewanta Jayasinghe, MD

International Senior Fellow in Colorectal Surgery

The Royal London Hospital

Barts Health NHS Trust

London

UK

Disclosures

JDJ declares that he has no competing interests.

Peer reviewers

John Abercrombie, FRCS

General and Colorectal Surgeon

Queen’s Medical Centre

Nottingham

UK

Biography

JA is a former Clinical Lead for General Surgery, Getting It Right First Time.

Disclosures

JA is a council member of the Royal College of Surgeons of England.

Editors

Emma Quigley,

Section Editor, BMJ Best Practice

Disclosures

EQ declares that she has no competing interests.

Rachel Wheeler,

Lead Section Editor, BMJ Best Practice

Disclosures

RW declares that she has no competing interests.

Julie Costello,

Comorbidities Editor, BMJ Best Practice

Disclosures

JC declares that she has no competing interests.

Adam Mitchell,

Drug Editor, BMJ Best Practice

Disclosures

AM declares that he has no competing interests.

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