What is the procedure for performing a rectal disimpaction?

Rectal Disimpaction Procedure

Perform digital fragmentation and extraction of the impacted stool after administering appropriate analgesia and/or anxiolytic medication, followed by water or oil retention enema to facilitate passage of remaining stool. 1

Pre-Procedure Assessment

Before attempting disimpaction, confirm the diagnosis and rule out contraindications:

• Perform digital rectal examination (DRE) to identify a large mass of dry, hard stool in the rectum 1
• Rule out complications such as perforation or bleeding before proceeding 1
• Note that proximal rectal or sigmoid impactions may not be palpable on DRE 1
• Provide close patient monitoring during the procedure, especially in patients with significant stool burden, as bradycardic arrest and death have been reported during rectal manipulation 2

Step-by-Step Disimpaction Technique

1. Patient Preparation

• Administer analgesia and/or anxiolytic before the procedure 3, 1, 2
• Position patient in left lateral decubitus or lithotomy position (general medical knowledge)
• Consider mild sedation or anesthesia for difficult cases 3

2. Manual Disimpaction

• Perform digital fragmentation and extraction of the fecal mass using a gloved, lubricated finger 1, 4
• Break up the impacted stool into smaller pieces that can be removed manually 1
• Work systematically to fragment and extract as much stool as possible 4

3. Enema Administration

After manual disimpaction, administer retention enema to facilitate passage of remaining stool 1:

• Hypertonic sodium phosphate enema 1
• Docusate sodium enema 1
• Warm oil retention enema (including arachis/mineral oil) 3, 1
• Bisacodyl enema 1
• Glycerol suppositories may also be used as a rectal stimulant 3

4. Alternative Approach for Proximal Impaction

If impaction extends beyond the rectum into the sigmoid colon:

• Administer oral or nasogastric polyethylene glycol (PEG) solutions containing electrolytes to soften or wash out stool 1, 4
• Consider adding bisacodyl suppository (one rectally daily-BID), lactulose 30-60 mL BID-QID, sorbitol 30 mL every 2 hours × 3, magnesium hydroxide 30-60 mL daily-BID, or magnesium citrate 8 oz daily 3, 1
• Tap water enema until clear may be necessary 3

5. Refractory Cases

• Manual evacuation under anesthesia if disimpaction does not occur after oral and rectal treatment 3, 5
• Endoscopic disimpaction with rectal lavage using a sigmoidoscope 6
• Surgical intervention is reserved for peritonitis from bowel perforation 6

Critical Contraindications for Enemas

Do not use enemas in the following situations 1:

• 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

Post-Procedure Management

Immediate Follow-Up

• Implement a maintenance bowel regimen immediately after disimpaction to prevent recurrence 1
• Preferred laxatives include osmotic laxatives (PEG, lactulose, magnesium salts) and stimulant laxatives (senna, cascara, bisacodyl, sodium picosulfate) 1
• Avoid bulk laxatives such as psyllium, especially in patients with opioid-induced constipation or limited mobility 1

Long-Term Prevention

• Increase daily water and fiber intake (if adequate fluid intake and physical activity present) 3, 6
• Limit medications that decrease colonic motility 6
• Educate patients to attempt defecation at least twice daily, usually 30 minutes after meals 1
• Ensure access to toilets, especially for patients with decreased mobility 1

Common Pitfalls

Monitor for vasovagal response: Rectal manipulation can trigger severe bradycardia and cardiac arrest through vagal stimulation 2. Maintain continuous cardiac monitoring during the procedure, particularly in elderly patients or those with significant impaction.

Avoid delaying treatment: Early recognition and prompt treatment minimize complications including bowel obstruction, stercoral ulcer, perforation, peritonitis, or cardiopulmonary collapse 6.

Special attention to elderly patients: They are at higher risk for severe constipation and fecal impaction; PEG (17 g/day) offers an efficacious and tolerable solution with a good safety profile 1.