adynamic ileus

Adynamic ileus is the failure of passage of enteric contents through the small bowel and colon that are not mechanically obstructed. Essentially it represents the paralysis of intestinal motility.

Clinical presentation

Patients may be asymptomatic or present with symptoms similar to mechanical bowel obstruction such as nausea/vomiting, distension, and reduced or absent bowel movements. Bowel sounds may also be absent.

Pathology

Etiology

Adynamic ileus can be caused by a number of conditions:

The cause of ileus is thought to be complex and multifactorial, involving bowel inflammation , inhibitory neural reflexes , and neurohormonal peptides .

Postoperative ileus vs. paralytic ileus

Some degree of ileus is a normal and expected finding after abdominal surgery, including C-section . Conventional recovery times have been reported at :

  • small intestine: 0-24 hours 
  • stomach: 24-48 hours
  • colon: 48-72 hours

These intervals, however, may be overestimations.

Prolonged postoperative ileus (>72 hours) has been termed "paralytic" ileus by some and is concerning for small bowel obstruction, bowel perforation, peritonitis, and intra-abdominal abscess.

Improving postoperative ileus is often determined clinically as much as radiographically, with the resumption of oral intake and flatus.

Radiographic features 

Plain radiograph
  • generalized, uniform, gaseous distension of the large and small bowel
  • when localized, there may be a sentinel loop

History and etymology

"Ileus" ultimately derives from είλειν ("to twist"), which also gave rise to the section of the bowel termed the "ileum". At one time what we now call ileus had been called the "iliack passion" because it was believed that the intestines were twisted .