What is the treatment for constipation due to ileus?

Treatment for Constipation Due to Ileus

For constipation due to ileus, the treatment approach should focus on prokinetic agents like metoclopramide (10-20 mg PO QID) combined with osmotic laxatives such as polyethylene glycol, while addressing the underlying cause of the ileus. 1

Initial Assessment and Management

• Rule out mechanical obstruction through physical examination and abdominal imaging before initiating treatment 1
• Discontinue any non-essential constipating medications, particularly opioids, antipsychotics, and anticholinergics that may be contributing to the ileus 1, 2
• Assess and treat other potential causes such as electrolyte abnormalities (hypercalcemia, hypokalemia), hypothyroidism, or diabetes mellitus 1

Pharmacological Interventions

First-line Treatments:

• Consider a prokinetic agent such as metoclopramide (10-20 mg PO QID) to stimulate gastrointestinal motility 1
• Initiate osmotic laxatives, with polyethylene glycol (PEG) being the preferred agent (1 capful/8 oz water BID) 1, 3
• For mild cases, fiber supplementation may be considered if adequate fluid intake and physical activity are possible 1

For Opioid-Induced Ileus:

• Methylnaltrexone 0.15 mg/kg subcutaneously every other day (not more than once daily) is recommended for opioid-induced constipation not responding to standard laxative therapy 1, 4
• Methylnaltrexone should NOT be used in patients with postoperative ileus or mechanical bowel obstruction 1
• Other peripherally acting μ-opioid receptor antagonists (PAMORAs) may be beneficial for severe cases 4, 5

For Persistent Constipation:

• Add stimulant laxatives such as bisacodyl (10-15 mg daily to TID) with a goal of one non-forced bowel movement every 1-2 days 1
• For impaction, administer glycerine suppositories or perform manual disimpaction following pre-medication with analgesic and anxiolytic 1
• Consider additional laxatives if needed: bisacodyl suppository (one rectally daily-BID), lactulose (30-60 mL BID-QID), sorbitol (30 mL every 2 hours × 3, then PRN), magnesium hydroxide (30-60 mL daily-BID), or magnesium citrate (8 oz daily) 1

Non-Pharmacological Interventions

• Increase fluid intake and encourage physical activity when appropriate 1
• Provide intravenous hydration if oral intake is inadequate 1, 5
• Consider tap water enemas until clear for severe cases 1

Special Considerations

• In patients with clozapine-induced ileus, dose reduction of the antipsychotic medication may be necessary 2, 6
• For critically ill patients, prevention with bowel management protocols using osmotic laxatives appears to be safe 5, 7
• In patients with cystic fibrosis and distal intestinal obstruction syndrome (DIOS), aggressive treatment with oral laxatives (polyethylene glycol) or intestinal lavage with balanced osmotic electrolyte solution is required 3

Monitoring and Follow-up

• Reassess for cause and severity of constipation if symptoms persist 1
• Monitor for adequate bowel movements with a goal of one non-forced bowel movement every 1-2 days 1
• Recheck for impaction or obstruction if symptoms worsen 1

Caution

• Avoid stimulant laxatives in suspected mechanical obstruction 1, 7
• Severe constipation can progress to paralytic ileus, which can be life-threatening and may require surgical intervention if not properly managed 2, 6