Ileus is a partial or complete non-mechanical blockage of the small and/or large intestine.
There are two types of intestinal obstructions , mechanical and non-mechanical. Mechanical obstructions occur because the bowel is physically blocked and its contents cannot 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. By contrast, non-mechanical obstruction, called ileus, occurs because the rhythmic contractions that move material through the bowel (called peristalsis) stop.
The total rate of bowel obstruction due both to mechanical and non-mechanical causes is one in 1,000 people. Meconium ileus accounts for 9–33 percent of bowel obstructions in newborns.
Causes and symptoms
Ileus is most often associated with an infection of the peritoneum (the membrane lining the abdomen) or other intra-abdominal infections such as appendicitis . 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.
Ileus can also be caused by kidney diseases, especially when potassium levels are decreased (a condition called hypokalemia). Narcotics and certain chemotherapy drugs, such as vinblastine (Velban, Velsar) and vincristine (Oncovin, Vincasar PES, Vincrex) can also cause ileus. Infants with cystic fibrosis are more likely to experience meconium ileus (obstruction of a dark green material in the intestine in newborns).
When the bowel stops functioning, the following symptoms occur:
When to call the doctor
A healthcare professional should be contacted if a child experiences persistent abdominal distention, is unable to have normal bowel movements, or exhibits other symptoms of ileus. Persistent abdominal pain and chronic or prolonged constipation are also reasons to call the doctor.
When a doctor listens with a stethoscope to the abdomen of a child suffering from ileus, 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 may also be useful in diagnosing 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.
Patients may be treated with supervised bed rest in a hospital and bowel rest, where nothing is taken by mouth, and patients are fed intravenously or through the use of a nasogastric tube, 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 or death (necrosis) of intestinal tissue, 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 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, homeopaths and practitioners of traditional Chinese medicine can recommend therapies that may help to reinstate peristalsis.
Following abdominal surgery, uncomplicated cases of ileus can be managed by minimizing the amount of food the patient consumes, ensuring adequate fluid intake, and correcting any electrolyte disturbances such as low potassium.
The outcome varies depending on the cause of ileus. When ileus results from abdominal surgery, the condition is usually temporary and lasts approximately 24–72 hours. The prognosis is less certain in cases in which death of intestinal tissue occurs; surgery becomes necessary to remove the necrotic tissue. In children with cystic fibrosis in which meconium ileus becomes evident soon after birth, the prognosis is linked with the primary disease; the median age of survival for cystic fibrosis patients is 30 years. However, new interventions in the treatment of CF are increasing the age span of people with CF every year.
Most cases of ileus are not preventable. Surgery to remove a tumor or other mechanical obstruction may help to prevent a recurrence.
In cases in which electrolyte imbalance is the cause of ileus, it is important to treat the underlying cause of the imbalance, which in many cases is related to chronic vomiting and/or diarrhea, poor fluid and/or food intake, or abuse of laxatives and diuretics (such as in individuals with bulimia nervosa ).
When their child is diagnosed with ileus, parents may be concerned about the necessity of surgery to correct the problem. Surgery, however, is considered only in medical emergencies and for patients for whom more conservative treatments have failed.
Bulimia nervosa —An eating disorder characterized by binge eating and inappropriate compensatory behavior, such as vomiting, misusing laxatives, or excessive exercise.
Computed tomography (CT) —An imaging technique in which cross-sectional x rays of the body are compiled to create a three-dimensional image of the body's internal structures; also called computed axial tomography.
Meconium —A greenish fecal material that forms the first bowel movement of an infant.
Peritoneum —The transparent membrane lining the abdominal and pelvic cavities (parietal peritoneum) and the membrane forming the outer layer of the stomach and interstines (visceral peritoneum). Between the visceral and parietal peritoneums is a potential space called the peritoneal cavity.
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Tish Davidson, AM Stephanie Dionne Sherk
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