Can an enema be used to treat rectal fecal impaction?

Treatment of Rectal Fecal Impaction with Enemas

Enemas are an effective and recommended treatment option for rectal fecal impaction, particularly when used in combination with manual disimpaction after appropriate premedication with analgesics and/or anxiolytics. 1, 2

Initial Assessment and Approach

• Confirm rectal fecal impaction: Digital rectal examination is essential to confirm the presence of hard stool mass in the rectum
• Rule out contraindications for enema use, including:
  • Neutropenia or thrombocytopenia
  • Paralytic ileus or intestinal obstruction
  • Recent colorectal or gynecological surgery
  • Recent anal or rectal trauma
  • Severe colitis, inflammation or infection of the abdomen
  • Toxic megacolon
  • Undiagnosed abdominal pain
  • Recent radiotherapy to the pelvic area 2

Treatment Algorithm

1. First-line treatment: Manual disimpaction following premedication with analgesic ± anxiolytic 1

   • This should be performed gently to avoid rectal trauma
   • Premedication is essential for patient comfort

2. Administer enema:

   • Glycerine suppository ± mineral oil retention enema 1
   • Mineral oil enema (120 mL for adults) 3
   • Position patient properly (left-side or knee-chest position) 3
   • Gently insert enema tip with slight side-to-side movement
   • Squeeze bottle until nearly all liquid is gone
   • Expect bowel movement within 2-15 minutes 3

3. For persistent impaction:

   • Consider tap water enema until clear 1
   • Add bisacodyl suppository (one rectally daily-BID) 1
   • Consider polyethylene glycol (1 capful/8 oz water BID) 1, 4

Special Considerations

• Elderly patients: Use PEG 17g daily as it has a favorable safety profile 2
• Chronic kidney disease: Avoid phosphate enemas; use PEG-based preparations 2
• Check baseline electrolytes and renal function before using phosphate enemas 2
• Do not retain enema solution for longer than 15 minutes 3

Follow-up and Prevention

After successful disimpaction:

• Implement a maintenance bowel regimen to prevent recurrence 1, 5
• Consider adding stimulant laxatives (bisacodyl 10-15 mg daily) 1, 2
• Increase fluid intake (at least 2L daily unless contraindicated) 2
• Increase dietary fiber if appropriate (25g daily) 2
• Consider scheduled toileting 30 minutes after meals 2

Potential Complications

• If left untreated, fecal impaction can lead to serious complications including:
  • Bowel obstruction
  • Stercoral ulceration
  • Perforation
  • Peritonitis
  • Hemodynamic instability 5

Enemas are a well-established treatment for rectal fecal impaction and should be considered alongside manual disimpaction as part of the initial management strategy. However, they should be used with caution in patients with contraindications and always following appropriate premedication for patient comfort.