What is the management for a fecal impaction in the rectum?

Management of Fecal Impaction in the Rectum

For fecal impaction in the rectum, management involves digital fragmentation and extraction of the stool, followed by enemas or suppositories to facilitate passage, and implementation of a maintenance bowel regimen to prevent recurrence. 1

Initial Assessment and Diagnosis

• Confirm diagnosis through digital rectal examination (DRE) to identify the fecal mass
• Note that watery stool leakage (overflow) may be present despite the impaction
• Assess for complications including:
  • Urinary tract obstruction
  • Perforation of the colon
  • Dehydration and electrolyte imbalance
  • Renal insufficiency
  • Stercoral ulcers and rectal bleeding 1, 2

Management Algorithm

Step 1: Rule Out Contraindications

• Before proceeding with manual disimpaction or enemas, ensure patient does not have:
  • Neutropenia (WBC < 0.5 cells/μL)
  • Thrombocytopenia
  • Paralytic ileus or intestinal obstruction
  • Recent colorectal or gynecological surgery
  • Recent anal or rectal trauma
  • Severe colitis or abdominal infection
  • Toxic megacolon
  • Undiagnosed abdominal pain
  • Recent pelvic radiotherapy 1

Step 2: Distal Fecal Impaction Treatment

1. Manual disimpaction:

   • Perform digital fragmentation of the stool mass
   • Extract accessible impacted stool 1, 3
   • This approach is successful in approximately 80% of cases 4

2. Follow with enemas or suppositories:

   • Water or oil retention enemas to soften remaining stool
   • Suppositories to facilitate passage through the anal canal 1
   • Options include:
     • Glycerin suppositories (lubricate and stimulate rectal motility)
     • Hypertonic sodium phosphate enemas (distend and stimulate rectal motility)
     • Docusate sodium enemas (soften stool by aiding water penetration)
     • Bisacodyl enemas (promote intestinal motility)
     • Warm oil retention enemas (cottonseed, olive oil) to lubricate and soften stool 1

Step 3: After Initial Disimpaction

• Once the distal colon has been partially emptied:
  • Administer polyethylene glycol (PEG) orally (17g daily mixed in 8oz water)
  • For proximal impaction without complete obstruction, use PEG solutions with electrolytes to soften or wash out stool 1, 5

Step 4: Severe Cases Management

• For severe impaction not responding to standard measures:
  • Consider endoscopic intervention
  • In cases of perforation or peritonitis, surgical intervention may be necessary 6, 2
  • For hemodynamically unstable patients or those with signs of gangrene/perforation, immediate surgical treatment is recommended 1

Prevention of Recurrence

1. Implement maintenance bowel regimen:

   • Regular use of osmotic laxatives (PEG preferred)
   • Consider adding stimulant laxatives (senna, bisacodyl) if needed 1, 5

2. Dietary modifications:

   • Adequate fluid intake
   • High-fiber diet (approximately 30g/day) 5

3. Lifestyle modifications:

   • Increased physical activity as tolerated
   • Establish regular toileting routine (attempt defecation 30 minutes after meals)
   • Optimize toileting position (use footstool to assist with defecation) 5

4. For opioid-induced constipation:

   • Prophylactic laxative therapy
   • Consider peripheral opioid antagonists for refractory cases 1, 5

Special Considerations

• Elderly patients require particular attention to assessment and prevention due to higher risk of fecal impaction 1, 5
• Post-treatment evaluation should include colonic evaluation by flexible sigmoidoscopy, colonoscopy, or barium enema after resolution 3
• Investigate underlying causes of constipation to prevent recurrence 3, 2

Complications to Monitor

• Bowel obstruction
• Stercoral ulceration and perforation
• Peritonitis
• Cardiopulmonary collapse with hemodynamic instability 2

The management of fecal impaction requires prompt intervention to prevent serious complications. Digital disimpaction followed by enemas and maintenance therapy represents the cornerstone of treatment, with surgical intervention reserved for cases with perforation or peritonitis.