Functional intestinal obstruction

Functional Intestinal Obstruction

Functional intestinal obstruction, also known as paralytic ileus, is a condition characterized by a failure of the intestines to propel their contents due to a lack of peristalsis, rather than a physical blockage. This condition can lead to significant abdominal discomfort and distension, and it is a common complication following abdominal surgery or in association with certain medical conditions.

Pathophysiology

Functional intestinal obstruction occurs when the normal coordinated muscular contractions of the intestines, known as peristalsis, are disrupted. This disruption can be due to:

• Postoperative ileus: A common cause, often seen after abdominal surgery, where the intestines temporarily lose their ability to contract effectively.
• Electrolyte imbalances: Conditions such as hypokalemia or hyponatremia can impair muscle function, including the muscles of the intestines.
• Medications: Certain drugs, particularly opioids, can reduce intestinal motility.
• Inflammatory conditions: Diseases such as pancreatitis or appendicitis can lead to ileus due to inflammation and irritation of the intestines.

Clinical Presentation

Patients with functional intestinal obstruction typically present with:

• Abdominal distension: Due to the accumulation of gas and fluids in the intestines.
• Nausea and vomiting: As a result of the inability to move contents through the gastrointestinal tract.
• Absence of bowel sounds: On auscultation, bowel sounds may be reduced or absent, indicating a lack of peristalsis.
• Constipation or obstipation: The inability to pass stool or gas.

Diagnosis

The diagnosis of functional intestinal obstruction is primarily clinical, supported by:

• Abdominal X-rays: May show dilated loops of bowel with air-fluid levels.
• CT scan: Can help rule out mechanical obstruction and assess for other intra-abdominal pathology.
• Electrolyte panel: To identify and correct any underlying electrolyte disturbances.

Management

The management of functional intestinal obstruction involves:

• Supportive care: Including intravenous fluids to maintain hydration and electrolyte balance.
• Nasogastric decompression: A nasogastric tube may be inserted to relieve gastric distension and vomiting.
• Correction of underlying causes: Such as electrolyte imbalances or discontinuation of offending medications.
• Gradual reintroduction of diet: Once bowel function begins to return, a gradual reintroduction of oral intake is recommended.

Prognosis

The prognosis for functional intestinal obstruction is generally good, especially when the underlying cause is identified and treated. Most cases resolve with conservative management, although prolonged ileus may require more intensive interventions.

Also see

• Mechanical bowel obstruction
• Peristalsis
• Postoperative complications
• Electrolyte imbalance