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 radiographs and clinical impression. Treatment is supportive, with nasogastric suction and IV fluids.
Etiology of Ileus
The most common cause of ileus is
Abdominal surgery
Other causes include
Intraperitoneal or retroperitoneal inflammation (eg, appendicitis, diverticulitis, perforated duodenal ulcer)
Retroperitoneal or intra-abdominal hematomas (eg, from ruptured abdominal aortic aneurysm, blunt abdominal trauma)
Metabolic disturbances (eg, hypokalemia)
Medications (eg, opioids, anticholinergics, sometimes calcium channel blockers)
Sometimes renal or thoracic disease (eg, lower rib fractures, lower lobe pneumonias, myocardial infarction)
Gastric and colonic motility disturbances after abdominal surgery are common. Handling of the bowel causes inflammatory processes and resultant decreased contractile activity (1). The small bowel is typically least affected, with motility and absorption returning to normal within hours after surgery. Stomach emptying is usually impaired for approximately 24 hours or more. The colon is often most affected and may remain inactive for 48 to 72 hours or more.
Etiology reference
1. Boeckxstaens GE, de Jonge WJ. Neuroimmune mechanisms in postoperative ileus [published correction appears in Gut. 2010 Jan;59(1):140]. Gut. 2009;58(9):1300-1311. doi:10.1136/gut.2008.169250
Symptoms and Signs of Ileus
Symptoms and signs of ileus include abdominal distention, nausea, vomiting, and vague discomfort. Pain rarely has the classic colicky pattern present in mechanical bowel obstruction. There may be obstipation or passage of slight amounts of watery stool.
Auscultation reveals a silent abdomen or minimal peristalsis. The abdomen is not tender unless the underlying cause is inflammatory.
Diagnosis of Ileus
Clinical evaluation
Sometimes radiographs
The most essential task is to distinguish ileus from intestinal obstruction. In both conditions, abdominal radiographs show gaseous distention of isolated segments of intestine. In postoperative ileus, however, gas may accumulate more in the colon than in the small bowel. Postoperative accumulation of gas in the small bowel often implies development of a complication (eg, obstruction, peritonitis).
Sometimes, radiographic findings are similar to those of intestinal obstruction; differentiation can be difficult unless clinical features clearly favor one or the other. A contrast-enhanced CT may help differentiate between the two and suggest an underlying cause of the ileus.
Treatment of Ileus
Nasogastric suction
IV fluids
Treatment of ileus involves continuous nasogastric suction, nothing by mouth, IV fluids and electrolytes, a minimal amount of sedatives, and avoidance of opioids and anticholinergic medications. Maintaining an adequate serum potassium level (> 4 mEq/L [> 4.00 mmol/L]) is especially important. Ileus persisting > 1 week probably has a mechanical obstructive cause, and laparotomy should be considered.
Key Points
There are many causes of ileus; abdominal surgery is the most common.
Auscultation reveals a silent abdomen or minimal peristalsis.
Distinguish ileus from intestinal obstruction.
Treat with nasogastric suction and IV fluids.
Avoid opioids and anticholinergic medications.
