How should constipation be evaluated and treated in an individual in their late 80s?

Management of Constipation in Patients in Their Late 80s

Start with polyethylene glycol (PEG) 17 g once daily as first-line pharmacological treatment after implementing non-pharmacological measures, and escalate systematically if no bowel movement occurs within 3-4 days. 1, 2

Initial Assessment: Key Factors Specific to the Late 80s Population

Before prescribing any laxative, obtain a complete medication list and withdraw unnecessary constipating drugs—particularly anticholinergics, antidepressants, and opioids that are common culprits in this age group. 1, 3 Document the patient's living situation (alone, with family, or in a nursing home) as this directly impacts toilet access and ability to implement recommendations. 4, 1 Perform a digital rectal examination to rule out fecal impaction, which is a distinct risk in elderly patients and requires immediate manual disimpaction before starting oral laxatives. 4, 1

Check for reduced activity of daily living, as this is significantly associated with constipation in nursing home residents (OR = 0.71, P < 0.001). 3 If the patient is on quetiapine for behavioral control in cognitive disease, consider tapering it off as it causes constipation through muscarinic receptor blockade and is often safe to discontinue when there is perceived lack of benefit. 2

Non-Pharmacological Measures: Implement These First

• Ensure easy toilet access, especially critical if the patient has decreased mobility—this single environmental modification markedly reduces recurrence and complications. 1, 2
• Optimize toileting habits: educate the patient to attempt defecation twice daily, 30 minutes after meals, straining no more than 5 minutes. 1, 2
• Increase fluid intake to at least 1.5 liters daily within patient limits. 1, 5
• Encourage physical activity and increased mobility as tolerated, even just bed-to-chair transfers. 4, 1
• Provide dietetic support to manage decreased oral intake from age-related anorexia or chewing difficulties. 1, 2

Pharmacological Treatment Algorithm

Step 1: First-Line Therapy

Initiate PEG 17 g once daily mixed with 8 oz water as the preferred laxative due to its excellent safety profile even in cardiac or renal failure, dysphagia, and limited chewing ability—it causes virtually no electrolyte disturbances and is proven safe for continuous use beyond 12 months. 1, 2, 5

Step 2: Dose Escalation (If No Bowel Movement in 3-4 Days)

Escalate PEG to 17 g twice daily (34 g total/day) and reassess after another 3-4 days. 1, 2

Step 3: Add Stimulant Laxative (If Still No Response After 3-4 Days)

Add bisacodyl 10-15 mg daily as a stimulant adjunct, with a maximum of 10 mg orally daily for regular use. 1, 2, 5 Senna (2 tablets every morning, maximum 8-12 tablets per day) is an effective alternative stimulant. 5

Step 4: Consider Rectal Measures (For Dysphagia or Recurrent Impaction)

For patients with swallowing difficulties or repeated fecal impaction, prioritize rectal therapies (suppositories or enemas) over oral agents. 1, 2 Use isotonic saline enemas (500-1000 mL) rather than sodium phosphate enemas, as the former have fewer adverse effects in elderly patients. 1, 2, 5

Step 5: Advanced Options (If Standard Laxatives Fail)

If constipation persists despite optimized oral laxatives, perform a digital rectal examination to rule out fecal impaction and bowel obstruction. 5 For opioid-induced constipation unresponsive to standard laxatives, peripherally acting mu-opioid receptor antagonists (PAMORAs such as methylnaltrexone, naloxegol, or naldemedine) can be considered, though they are costly. 1, 6, 7

Critical Safety Considerations: What to Absolutely Avoid

• Never use magnesium-containing laxatives (magnesium hydroxide, magnesium citrate) in any degree of renal impairment due to serious hypermagnesemia risk—always confirm normal renal function before considering these agents. 1, 2, 5
• Avoid bulk-forming laxatives (psyllium, methylcellulose) in non-ambulatory patients with limited fluid intake or mobility, as they increase the risk of mechanical bowel obstruction. 1, 2, 5
• Avoid liquid paraffin in bed-bound individuals or those with dysphagia because of high risk of aspiration lipoid pneumonia. 1, 2
• Do not use stool softeners (docusate) alone without stimulant or osmotic laxatives, as they lack efficacy for medication-induced constipation and should be reserved only for very specific situations where other options are contraindicated. 1, 5
• Replace sodium phosphate enemas with isotonic saline enemas to prevent electrolyte disturbances. 1, 2

Management of Fecal Impaction

If digital rectal examination confirms impaction, perform manual disimpaction (digital fragmentation and extraction) after pre-medication with analgesia ± anxiolysis to achieve complete clearance in one session. 4, 1 Reassess immediately after disimpaction to confirm complete clearance and rule out residual impaction. 1 Disimpaction should only be repeated if re-impaction occurs despite maintenance therapy, not on a scheduled basis. 1

Immediately after successful disimpaction, initiate PEG 17 g/day as first-line maintenance therapy to prevent recurrence. 1 Add bisacodyl suppository (one rectally daily to twice daily) if oral laxatives alone are insufficient. 1

Special Considerations for Opioid-Induced Constipation

All elderly patients receiving opioid analgesics must be prescribed a concomitant laxative prophylactically at initiation of opioid therapy—never wait for constipation to develop, as this causes unnecessary suffering and can lead to paralytic ileus. 1, 5, 6 The prophylactic regimen should include either a stimulant laxative (senna or bisacodyl) or PEG 17 g twice daily. 5, 7

Common Pitfalls to Avoid

• Do not wait for constipation to develop before starting laxatives in patients on opioids or antipsychotics. 5
• Do not prescribe fiber supplements to elderly patients with limited mobility or inadequate fluid intake, as this may exacerbate obstruction risk. 1
• Always rule out bowel obstruction before escalating laxative therapy, particularly if symptoms worsen despite treatment. 5
• Monitor patients on concurrent diuretics or cardiac glycosides for dehydration and electrolyte imbalances, since laxative use can amplify these risks. 1