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(Paralytic Ileus; Adynamic Ileus; Intestinal Paresis)


Parswa Ansari

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

Reviewed/Revised Apr 2023

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

  • Abdominal surgery and medications that interfere with the intestine’s movements are common causes.

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

  • The diagnosis is made by x-ray.

  • Most people get better with fluids given by vein and by not eating or drinking anything.

  • Some people need a thin suction tube passed through their nose into their stomach to relieve the buildup of gas and liquid.

Like intestinal obstruction Intestinal Obstruction An obstruction of the intestine is a blockage that completely stops or seriously impairs the passage of food, fluid, digestive secretions, and gas through the intestines. The most common causes... read more (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 medications, especially opioid analgesics and anticholinergic medications (see sidebar ). Ileus may also be caused by an infection inside the abdomen, such as appendicitis Appendicitis Appendicitis is inflammation and infection of the appendix. Often a blockage inside the appendix causes the appendix to become inflamed and infected. Abdominal pain, nausea, and fever are common... read more or diverticulitis Diverticulitis Diverticulitis is inflammation of one or more balloon-like sacs (diverticula). Infection may or may not develop. Diverticulitis usually affects the large intestine (colon). Left lower abdominal... read more Diverticulitis . Disorders outside the intestine, such as kidney failure Overview of Kidney Failure Kidney failure is the inability of the kidneys to adequately filter metabolic waste products from the blood. Kidney failure has many possible causes. Some lead to a rapid decline in kidney function... read more , an underactive thyroid gland Hypothyroidism Hypothyroidism is underactivity of the thyroid gland that leads to inadequate production of thyroid hormones and a slowing of vital body functions. Facial expressions become dull, the voice... read more Hypothyroidism , heart attack Acute Coronary Syndromes (Heart Attack; Myocardial Infarction; Unstable Angina) Acute coronary syndromes result from a sudden blockage in a coronary artery. This blockage causes unstable angina or a heart attack (myocardial infarction), depending on the location and amount... read more Acute Coronary Syndromes (Heart Attack; Myocardial Infarction; Unstable Angina) , or abnormal levels of blood electrolytes (low potassium levels Hypokalemia (Low Level of Potassium in the Blood) In hypokalemia, the level of potassium in blood is too low. A low potassium level has many causes but usually results from vomiting, diarrhea, adrenal gland disorders, or use of diuretics. A... read more or high calcium levels Hypercalcemia (High Level of Calcium in the Blood) In hypercalcemia, the level of calcium in blood is too high. A high calcium level may result from a problem with the parathyroid glands, as well as from diet, cancer, or disorders affecting... read more Hypercalcemia (High Level of Calcium in the Blood) , 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.

Treatment of Ileus

  • Temporary restriction of food and fluids by mouth

  • Fluids given by vein

  • Suction via nasogastric tube

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.

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