Ileus
Definition
Ileus is a partial or complete non-mechanical blockage of the small and/or large intestine. The term "ileus" comes from the Latin word for
colic.
Description
There are two types of
intestinal obstructions, mechanical and non-mechanical. Mechanical obstructions occur because the bowel is physically blocked and its contents can not pass the point of the obstruction. This happens when the bowel twists on itself (volvulus) or as the result of hernias, impacted feces, abnormal tissue growth, or the presence of foreign bodies in the intestines.
Unlike mechanical obstruction, non-mechanical obstruction, called ileus or paralytic ileus, occurs because peristalsis stops. Peristalsis is the rhythmic contraction that moves material through the bowel. Ileus is most often associated with an infection of the peritoneum (the membrane lining the abdomen). It is one of the major causes of bowel obstruction in infants and children.
Another common cause of ileus is a disruption or reduction of the blood supply to the abdomen. Handling the bowel during abdominal surgery can also cause peristalsis to stop, so people who have had abdominal surgery are more likely to experience ileus. When ileus results from abdominal surgery the condition is often temporary and usually lasts only 48-72 hours.
Ileus sometimes occurs as a complication of surgery on other parts of the body, including
joint replacement or chest surgery.
Ileus can also be caused by kidney diseases, especially when potassium levels are decreased. Heart disease and certain
chemotherapy drugs, such as vinblastine (Velban, Velsar) and vincristine (Oncovin, Vincasar PES, Vincrex), also can cause ileus. Infants with
cystic fibrosis are more likely to experience meconium ileus (a dark green material in the intestine). Over all, the total rate of bowel obstruction due both to mechanical and non-mechanical causes is one in one thousand people (1/1,000).
Causes and symptoms
When the bowel stops functioning, the following symptoms occur:
- abdominal cramping
- abdominal distention
- nausea and vomiting
- failure to pass gas or stool
Diagnosis
When a doctor listens with a stethoscope to the abdomen there will be few or no bowel sounds, indicating that the intestine has stopped functioning. Ileus can be confirmed by x rays of the abdomen,
computed tomography scans (CT scans), or ultrasound. It may be necessary to do more invasive tests, such as a
barium enema or upper GI series, if the obstruction is mechanical. Blood tests also are useful in diagnosing paralytic ileus.
Barium studies are used in cases of mechanical obstruction, but may cause problems by increasing pressure or intestinal contents if used in ileus. Also, in cases of suspected mechanical obstruction involving the gastrointestinal tract (from the small intestine downward) use of barium x rays are contraindicated, since they may contribute to the obstruction. In such cases a barium enema should always be done first.
Treatment
Patients may be treated with supervised bed rest in a hospital and bowel rest. Bowel rest means that nothing is taken by mouth and patients are fed intravenously or through the use of a nasogastric tube. A nasogastric tube is a tube inserted through the nose, down the throat, and into the stomach. A similar tube can be inserted in the intestine. The contents are then suctioned out. In some cases, especially where there is a mechanical obstruction, surgery may be necessary.
Drug therapies that promote intestinal motility (ability of the intestine to move spontaneously), such as cisapride and vasopressin (Pitressin), are sometimes prescribed.
Alternative treatment
Alternative practitioners offer few treatment suggestions, but focus on prevention by keeping the bowels healthy through eating a good diet, high in fiber and low in fat. If the case is not a medical emergency, homeopathic treatment and
traditional Chinese medicine can recommend therapies that may help to reinstate peristalsis.
Prognosis
The outcome of ileus varies depending on its cause.
Prevention
Most cases of ileus are not preventable. Surgery to remove a tumor or other mechanical obstruction will help prevent a recurrence.
Some measures that have been recommended to minimize the severity of postoperative ileus or shorten its duration include making sure that any electrolyte imbalances are corrected, and using nonopioid medications to relieve
pain, as opioid drugs (including morphine, oxycodone, and codeine) tend to cause
constipation. One group of drugs that shows promise for treating abdominal pain is a class of medications known as kappa-opioid agonists. As of 2004, however, these drugs are still under investigation for controlling visceral pain in humans.
Resources
Books
Beers, Mark H., MD, and Robert Berkow, MD, editors. "Ileus." Section 3, Chapter 25. In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.
Periodicals
Baig, M. K., and and S. D. Wexner. "Postoperative Ileus: A Review." Diseases of the Colon and Rectum 47 (April 2004): 516-526.
Lassandro, F., N. Gagliardi, M. Scuderi, et al. "Gallstone Ileus Analysis of Radiological Findings in 27 Patients." European Journal of Radiology 50 (April 2004): 23-29.
Pavone, P., T. Johnson, P. S. Saulog, et al. "Perioperative Morbidity in Bilateral One-Stage Total Knee Replacements." Clinical Orthopaedics and Related Research 421 (April 2004): 155-161.
Riviere, P. J. "Peripheral Kappa-Opioid Agonists for Visceral Pain." British Journal of Pharmacology 141 (April 2004): 1331-1334.
Other
"Bowel Paralysis." Trigan Oncology Associates Page. http://www.trigan.com/ileus.htm.
"Intestinal Obstruction." HealthAnswers.com. 〈http://www.healthanswers.com/database/ami/converted/000260.html〉.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
ileus
[il´e-us] failure of appropriate forward movement of bowel contents. It may be secondary to either mechanical obstruction of the bowel
(mechanical ileus) or a disturbance in neural stimulation
(adynamic ileus). Ileus is a surgical emergency that may or may not require surgical intervention; the cause needs to be established promptly.
Adynamic (or paralytic) ileus often accompanies peritonitis and is also found accompanying the colicky pains of gallstones or kidney stones; following spinal cord injury, pneumonia, or other generalized conditions; or being caused by peritoneal contamination by pus (from a perforated appendix) or acid (from a perforated ulcer). Mechanical ileus is that due to adhesions, ischemia, tumor, or stone and requires prompt decompression of the bowel to prevent perforation.
Symptoms. The principal symptoms of ileus are abdominal pain and distention, constipation, and vomiting in which the vomitus may contain fecal material. If the intestinal obstruction is not relieved, the circulation in the wall of the intestine is impaired and the patient appears extremely ill with symptoms of
shock and
dehydration.
Treatment. Distention of the abdomen is relieved by decompression, which involves intubation with a long, balloon-tipped tube (e.g.,
miller-abbott tube) that extends to the site of the obstruction, and use of constant suction. Because of the disruption in absorption of fluids and nutrients from the intestinal tract, fluids, electrolytes, and glucose are given intravenously. Surgical intervention to remove the cause of ileus is usually necessary when the obstruction is complete or the bowel is likely to become gangrenous. The type of surgical procedure will depend on the condition of the bowel and the cause of the obstruction. In some cases ileostomy or colostomy, either temporary or permanent, may be necessary. In cases of paralytic ileus due to causes other than contamination by pus or acid, tube decompression may be sufficient, but even in these patients, surgery may be needed to protect the bowel from overdistention and perforation. See also
intestinal obstruction for patient care.
adynamic ileus that caused by inhibition of bowel motility; see
ileus.
mechanical ileus that caused by a mechanical cause, such as hernia, adhesions, or volvulus; see
ileus.
meconium ileus ileus in the newborn due to intestinal obstruction by thick
meconium.
spastic ileus that due to persistent contracture of a bowel segment.
ileus subpar´ta ileus due to pressure of the gravid uterus on the pelvic colon.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.