Ileus

Background

• Failure or insufficiency in the peristalsis movement of the gastrointestinal tract which normally moves GI contents from mouth to anus.
• Thought to be caused by a disruption in either the neural and/or neuro-hormonal reflexes that normally regulate bowel motility.
• Multiple causes possible - likely an inflammatory condition
  • Opioid-induced
  • Post-operative (irritation +/- opioids)
  • Electrolyte imbalance (hypokalemia, hypomagnesemia)
  • Colonic pseudo-obstruction (aka Ogilvie's syndrome)
  • Gallstone ileus, pancreatitis
• Peritonitis (e.g. from infection, malignancy, trauma)
• Clostridium difficile colitis
  • Burns, acute radiation syndrome
  • Spastic ileus (rare: porphyria or lead poisoning)

Clinical Features

• Abdominal pain/distension
• Nausea/vomiting, inability to tolerate PO/enteral feeding
• Constipation
• Absent or hypoactive bowel sounds
• Can produce intestinal ischemia, intestinal perforation, abdominal compartment syndrome

Differential Diagnosis

• Small bowel obstruction
• See constipation, abdominal pain

Evaluation

• BMP, Mg
• Abdominal X-ray: air fluid levels, air in bowel, distended bowel
• Evaluate for underlying causes
• If concern for SBO, CT abdomen

Management

• Treat underlying causes
• Avoid excessive IV fluids (bowel edema worsens ileus)
• Avoid opioids
• Pro-motility agents
  • Metoclopramide, erythromycin
• Opioid antagonist: methylnaltrexone
• Ogilvie's syndrome: Neostigmine 2mg IV

See Also

• Small bowel obstruction
• Toxic megacolon