• A condition caused by the lack of intestinal PERISTALSIS or INTESTINAL MOTILITY without any mechanical obstruction. This interference of the flow of INTESTINAL CONTENTS often leads to INTESTINAL OBSTRUCTION. Ileus may be classified into postoperative, inflammatory, metabolic, neurogenic, and drug-induced.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• Acute obstruction of the intestines preventing passage of the contents of the intestines.
  Human Phenotype Ontology (HPO)
  The Human Phenotype Ontology Project, 2025
• Decrease in peristalsis in the absence of a mechanical bowel obstruction.
  NCI
  U.S. National Cancer Institute, 2021
• A disorder characterized by failure of the ileum to transport intestinal contents.
  Common Terminology Criteria for Adverse Events
  U.S. National Institutes of Health, 2021
• Ileus is a temporary arrest of intestinal peristalsis. It occurs most commonly after abdominal surgery, particularly when the intestines have been manipulated. Symptoms are nausea, vomiting, and vague abdominal discomfort. Diagnosis is based on x-ray findings and clinical impression. Treatment is supportive, with nasogastric suction and...
  Merck Manuals
  Merck & Co., Inc., 2025
• Ileus occurs from hypomotility of the gastrointestinal tract in the absence of mechanical bowel obstruction. Although the exact pathogenesis of ileus remains multifactorial and complex, the clinical picture appears to be transiently impaired propulsion of intestinal contents.
  Medscape
  WebMD, 2025
• Ileus is a slowing of GI motility accompanied by distention, in the absence of a mechanical intestinal obstruction. It is a diagnosis of exclusion after bowel obstruction has been ruled out. It usually occurs in response to physiologic stress, including surgery, sepsis, metabolic derangements, and GI diseases.
  Epocrates
  Athenahealth, Inc., 2019