Ileus

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Last reviewed: 14 Apr 2025
Last updated: 22 Apr 2024

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • nausea and vomiting
  • abdominal distention or tenderness
  • no features of mechanical obstruction or peritoneal inflammation (e.g., abdominal hernia, peritoneal signs)
Full details

Other diagnostic factors

  • obstipation (absolute constipation)
  • discomfort and abdominal pain
  • decreased or hypoactive bowel sounds
  • hypovolaemia
Full details

Risk factors

  • abdominal surgery
  • acute/systemic illness (e.g., myocardial infarction, pneumonia, acute cholecystitis, pancreatitis, sepsis, multi-organ trauma)
  • non-abdominal surgery
  • electrolyte imbalance
  • opioid analgesics, anticholinergics, or anaesthetic gases
  • comorbidities (e.g., diabetes mellitus, cardiovascular insufficiency, Chagas disease, scleroderma)
Full details

Diagnostic investigations

1st investigations to order

  • FBC
  • serum electrolytes
  • serum magnesium
  • urea and creatinine
  • arterial blood gases
  • abdomen and pelvis CT scan (with intravenous contrast and oral water-soluble contrast)
Full details

Investigations to consider

  • serum LFTs
  • serum lipase or amylase
  • small bowel series with oral water-soluble contrast
  • gastric emptying study
Full details

Treatment algorithm

ACUTE

postoperative ileus

non-surgical cause

ONGOING

ileus lasting 4 days or longer post-surgery (prolonged ileus)

Contributors

Expert advisers

John Abercrombie, FRCS

General and Colorectal Surgeon

Queen's Medical Centre

Nottingham

UK

Disclosures

JA is a member of the Council of The Royal College of Surgeons of England and Clinical Lead for General Surgery, Getting It Right First Time. JA provides expert advice regarding suitability of surgical treatments for Spire Healthcare.

Acknowledgements

BMJ Best Practice would like to gratefully acknowledge the previous expert contributor, whose work has been retained in parts of the content:

Steven D. Wexner MD, PhD (Hon), FACS, FRCS, FRCS (Ed), FRCSI (Hon)

Director, Digestive Disease Center

Professor and Chair, Department of Colorectal Surgery

Cleveland Clinic

Weston

FL

Disclosures

SDW has received consulting fees, stock options, and royalties from the following companies. These relationships are ongoing. Consulting - Intuitive Surgical, Karl Storz Endoscopy America, Medtronic, TiGenix. Royalties - Covidien, Intuitive Surgical, Karl Storz Endoscopy America, Unique Surgical Innovations. There are no relevant disclosures to the submitted work.

Peer reviewers

Michele Lucarotti, MD, FRCS

Consultant General & Colorectal Surgeon

Gloucestershire Royal Hospital

Gloucester

UK

Disclosures

ML declares that she has no competing interests.

Stephen Chapman, MBChB, BSc(Hons), MRCS(Eng)

NIHR Doctoral Research Fellow

General Surgery Registrar

Leeds Institute of Medical Research

University of Leeds

Leeds

UK

Disclosures

SC declares that he has no competing interests.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

Wattchow D, Heitmann P, Smolilo D, et al. Postoperative ileus - an ongoing conundrum. Neurogastroenterol Motil. 2021 May;33(5):e14046. Abstract

Gustafsson UO, Scott MJ, Hubner M, et al. Guidelines for perioperative care in elective colorectal surgery: enhanced recovery after surgery (ERAS®) society recommendations: 2018. World J Surg. 2019 Mar;43(3):659-95.Full text  Abstract

Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication].Full text

Powell-Tuck J, Gosling P, Lobo DN, et al. British consensus guidelines on intravenous fluid therapy for adult surgical patients (GIFTASUP). March 2011 [internet publication].Full text

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.
  • Ileus images
  • Differentials

    • Mechanical bowel obstruction
    • Pseudo-obstruction (Ogilvie's syndrome)
    • Gastroenteritis
    More Differentials
  • Guidelines

    • Guidelines for perioperative care in elective colorectal surgery: Enhanced Recovery After Surgery (ERAS®) Society recommendation
    • Commissioning guide: emergency general surgery (acute abdominal pain)
    More Guidelines
  • Videos

    Nasogastric tube insertion animated demonstration

    More videos
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