What is the definition or description of: paralytic ileus?

Gut "Turned Off": Food propagates thru the intestine via the coordinated contraction of muscle within the intestinal wall--we call this peristalsis. This muscle function can be "turned off" temporarily by many different factors (narcotics, inflammation within the abdomen, inactivity, spinal problems, etc) leading to a functional obstruction of the intestine & secondary bloating, vomiting, abdominal pain, etc.

Temporary condition: A paralytic ileus is when the intestines which are basically muscular tubes are temporarily unable to contract and move intestinal contents through the GI tract. This is often caused by abdominal surgery but other causes could be infections and inflammatory bowel diseaese. It will usually resolve on its own.