Fecal impaction

Background

• Typically a complication of chronic constipation that results in the accumulation hardened fecal matter in the colon or rectum that cannot be spontaneously evacuated

Risk Factors

• elderly and young age
• chronic constipation
• lifestyle factors (immobility, low fiber diets, dehydration)
• medications that impair GI motility (anticholinergics, antipsychotics, opioids)
• anatomic abnormalities (malignancy, anorectal disease, Hirschsprung)
• neurologic conditions (dementia, spinal cord injury, cerebral palsy)

Clinical Features

History:

• abdominal pain or bloating
• nausea and vomiting
• obstipation
• agitation/confusion (elderly patients with neuropsychiatric conditions)
• urinary incontinence
• overflow stool incontinence

Physical exam:

• abdominal distention and/or tenderness
• palpable firm stool balls on digital rectal exam

Differential Diagnosis

Constipation

• Colorectal malignancy
• Diverticulitis
• Bowel obstruction
• Stercoral colitis

Evaluation

• digital rectal exam
• chemistry to evaluate for hypokalemia or hypercalcemia
• TSH if indicated
• Abdominal X-Ray to evaluate for air-fluid levels and free-air
• CT if severe presentation
  • Stercoral colitis is CT finding caused by impacted fecal material causing pressure edema and ischemia on the bowel wall. Left untreated, the condition can lead to wall ischemia, ulceration, and perforation.
    • Findings include colonic wall thickening, pericolonic fat stranding, and extraluminal bubbles of gas or abscess (signs of perforation); all of which are not found in uncomplicated fecal impaction.

Management

• Surgical intervention is recommended if there are signs of perforation or peritonitis
• For distal impactions, disimpaction and/or rectal suppositories or enemas are recommended.
• Proximal impactions typically respond better to oral laxatives
• Address risk factors and initiate a maintenance bowel regimen after initial disimpaction

Disposition

• Consider admission for patient's with stercoral colitis for aggressive bowel regimen and washout

See Also

• Constipation