Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link


(Paralytic Ileus; Adynamic Ileus; Intestinal Paresis)


Parswa Ansari

, MD, Hofstra Northwell-Lenox Hill Hospital, New York

Last full review/revision Apr 2020| Content last modified Apr 2020
Click here for the Professional Version

Ileus is a temporary lack of the normal muscle contractions of the intestines.

  • Abdominal surgery and drugs that interfere with the intestine’s movements are a common cause.

  • Bloating, vomiting, constipation, cramps, and loss of appetite occur.

  • The diagnosis is made by x-ray.

  • People are given nothing to eat or drink, and sometimes a thin suction tube is passed through the nose into the stomach.

Like intestinal obstruction (blockage), ileus prevents the passage of food, fluid, digestive secretions, and gas through the intestines. However, unlike intestinal obstruction, ileus is not caused by a physical blockage (such as a tumor or scar tissue) and rarely leads to rupture.

The most common cause of ileus is

  • Abdominal surgery

Ileus commonly occurs for 24 to 72 hours after abdominal surgery, particularly when the intestines have been manipulated.

Other causes include drugs, especially opioid analgesics and anticholinergic drugs (see Anticholinergic: What Does It Mean?). Ileus may also be caused by an infection inside the abdomen, such as appendicitis or diverticulitis. Disorders outside the intestine, such as kidney failure, an underactive thyroid gland, heart attack, or abnormal levels of blood electrolytes (low potassium levels or high calcium levels, for example), may cause ileus.

Symptoms of Ileus

The symptoms of ileus are abdominal bloating and pain caused by a buildup of gas and liquids, nausea, vomiting, severe constipation, loss of appetite, and cramps. People may pass watery stool.

Diagnosis of Ileus

  • A doctor's examination

  • X-rays

A doctor hears few of the sounds normally made by a functioning intestine (bowel sounds) or none at all through a stethoscope.

An x-ray of the abdomen shows bulging loops of intestine.

Treatment of Ileus

  • Temporary restriction of food and fluids by mouth

  • Fluids given by vein

  • Suction via nasogastric tube

With restriction of food and fluids by mouth, ileus usually resolves on its own after 1 to 3 days. During this time, fluids and electrolytes (such as sodium, chloride, and potassium) are given by vein (intravenously). Whenever possible, powerful pain relievers called opioid analgesics are stopped or reduced.

Severe vomiting is rare, but if it occurs, the buildup of gas and liquid caused by ileus must be relieved. Usually, a tube is passed through the nose into the stomach or small intestine (nasogastric tube), and suction is applied to relieve pressure and expansion (distention). The person is not allowed to eat or drink anything until normal intestinal function returns. Sometimes, if the problem involves mainly the large intestine, a tube is passed through the anus into the large intestine to relieve the pressure.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Others also read

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID