Last reviewed: 25 Sep 2021
Last updated: 01 Mar 2019



History and exam

Key diagnostic factors

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

Other diagnostic factors

  • obstipation (severe constipation with no passage of stool or flatus)
  • discomfort and abdominal cramping
  • decreased or hypoactive bowel sounds
  • hypovolaemia

Risk factors

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

Diagnostic investigations

1st investigations to order

  • serum electrolytes
  • serum magnesium
  • FBC
  • abdominal x-ray

Investigations to consider

  • serum LFTs
  • serum amylase
  • serum lipase
  • serum albumin and pre-albumin
  • abdomen and pelvis CT scan (with intravenous contrast and oral water-soluble contrast)
  • small bowel series
  • gastric emptying study

Treatment algorithm



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


Digestive Disease Center

Professor and Chair

Department of Colorectal Surgery

Cleveland Clinic




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.


Dr Steven D. Wexner would like to gratefully acknowledge the contribution of Dr Stephen P. Sharp to the update for this topic. Dr Wexner would also like to acknowledge Dr Ahmed Sami Chadi, and Dr Paula I. Denoya, previous contributors to this topic.


SPS, ASC, and PID declare that they have no competing interests.

Peer reviewers

David J. Hackam, MD, PhD

Associate Professor of Pediatric Surgery

University of Pittsburgh School of Medicine




DJH declares that he has no competing interests.

John Jenkins, MB CHB, FRCP

Consultant Colorectal Surgeon

St. Mark's Hospital




JJ declares that he has no competing interests.

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