Does Colace (Docusate) Work for Constipation?
No, Colace (docusate) does not work for constipation and should not be used. Multiple major guidelines explicitly recommend against its use due to lack of efficacy evidence, and the highest quality randomized controlled trial in hospice patients showed no benefit over placebo 1, 2.
Why Docusate Fails
Docusate has a flawed mechanism that doesn't translate to clinical benefit. While it theoretically works as a surfactant to allow water and lipids to penetrate stool, this mechanism has proven clinically ineffective in practice 1. The National Comprehensive Cancer Network (NCCN) explicitly states that docusate has not shown benefit and is therefore not recommended 1.
Key Evidence Against Docusate
The European Society for Medical Oncology (ESMO) specifically lists docusate under "Laxatives generally not recommended in advanced disease" 1
A 2013 randomized, double-blind, placebo-controlled trial in 74 hospice patients found no significant differences between docusate plus sennosides versus placebo plus sennosides in stool frequency, volume, consistency, difficulty of evacuation, or completeness of evacuation 2
A systematic review concluded that docusate use in palliative care is based on inadequate experimental evidence, with identified studies showing only small, clinically insignificant trends 3
A 2021 review specifically examining older adults found that docusate showed no benefits compared to placebo, while psyllium and sennosides were more effective 4
What Actually Works: Evidence-Based Alternatives
Use osmotic laxatives or stimulant laxatives as first-line agents instead. These have strong evidence supporting their efficacy 1.
First-Line Osmotic Laxatives
Polyethylene glycol (PEG) 17 grams mixed in 8 oz water once to twice daily is the preferred first-line agent with moderate quality evidence from the American Gastroenterological Association 1, 5
PEG draws water into the intestine to hydrate and soften stool, with proven efficacy for both short-term and long-term management over 6 months 5
PEG is virtually free from net gain or loss of sodium and potassium, making it safer than other osmotic agents 5
Lactulose and magnesium salts are alternative osmotic agents, though avoid magnesium in renal insufficiency due to hypermagnesemia risk 1, 5
First-Line Stimulant Laxatives
Bisacodyl 10-15 mg daily to three times daily with a goal of one non-forced bowel movement every 1-2 days 6, 1
Senna is equally effective and recommended by NCCN guidelines 1
Stimulant laxatives irritate sensory nerve endings to stimulate colonic motility, addressing the actual problem rather than just stool consistency 1
Practical Treatment Algorithm
Start with PEG 17 grams once to twice daily. If no bowel movement after 2-3 days, add bisacodyl 10-15 mg daily or senna 1, 5. Do not waste time with docusate.
Special Considerations for Opioid-Induced Constipation
Provide prophylactic treatment with stimulant laxatives or osmotic agents when initiating opioid therapy 1
Increase laxative doses when increasing opioid doses, as opioid-induced constipation does not resolve with tolerance 1
For refractory cases, consider peripherally acting μ-opioid receptor antagonists such as methylnaltrexone 0.15 mg/kg every other day 6, 1
When to Escalate Treatment
If constipation persists despite oral laxatives, assess for impaction, obstruction, hypercalcemia, hypokalemia, hypothyroidism, and diabetes 6
For impaction, use glycerine suppositories or manual disimpaction 6
Consider rectal bisacodyl, polyethylene glycol, or enemas if oral treatment fails 6
Critical Pitfalls to Avoid
Never rely solely on stool softeners like docusate without addressing bowel motility or water content - this approach is insufficient according to NCCN guidelines 1.
Never use bulk laxatives like psyllium for opioid-induced constipation - they are ineffective and may worsen symptoms 1, 5.
Never fail to provide prophylactic laxatives when starting opioids - this leads to significant patient discomfort and reduced medication adherence 1.