The incidence of paralytic ileus is high in comparison to mechanical obstruction but paralytic ileus is not as significant as mechanical obstruction. Mechanical obstruction occurs when movement of material through the intestines is physically blocked. If the obstruction blocks the blood supply to the intestine, the tissue may die, causing infection and gangrene. Risk factors are intestinal malignancy , Crohn's disease , hernia , and previous abdominal surgery. The incidence is 2 out of 2,000 people.
Prevention depends on the cause.
Some are not preventable. If the obstruction persists to long or the bowel is significantly damaged the bowel sounds decrease until they become silent. Paralytic ileus has decreased or absent bowel sound initially. This will relieve abdominal distention and vomiting . Surgery to relieve the obstruction may be necessary if decompression by nasogastric tube does not relieve the symptoms, or if strangulation of the bowel or gangrene is suspected.