What is the recommended treatment for constipation, specifically with Miralax (polyethylene glycol), after not having a bowel movement for 3 days?

Yes, Taking Miralax (Polyethylene Glycol) Is Appropriate for Constipation After 3 Days Without a Bowel Movement

You should take Miralax (polyethylene glycol/PEG) 17g mixed in 8 ounces of water once daily, as this is the first-line pharmacological treatment recommended by the American Gastroenterological Association for constipation. 1

Immediate Treatment Approach

Start with PEG 17g (one heaping tablespoon) mixed in 8 ounces of liquid once daily. 1 This typically produces a bowel movement within 1-3 days according to FDA labeling. 2

Why PEG (Miralax) Is the Right Choice

• PEG significantly increases bowel movements per week compared to placebo (by approximately 2-3 additional bowel movements weekly) and provides global symptom relief. 1
• The response to PEG has been shown to be durable over 6 months of use. 1
• PEG is safe for long-term use without causing electrolyte abnormalities or clinically significant side effects. 1
• Common side effects are mild and include abdominal distension, loose stool, flatulence, and nausea. 1

Supportive Measures to Take Concurrently

• Increase fluid intake, particularly if you typically drink less than average amounts of water daily. 3
• Increase dietary fiber if you have adequate fluid intake, as this can help with mild-to-moderate constipation. 3
• Engage in physical activity if appropriate for your condition. 3

If PEG Alone Is Insufficient After 2-3 Days

Add a stimulant laxative such as bisacodyl (5-10mg) or glycerin suppository, preferably administered 30 minutes after a meal to synergize with the gastrocolonic response. 1, 3 The goal is to achieve one non-forced bowel movement every 1-2 days. 1

Alternative Options If PEG Is Unavailable

• Fiber supplements such as psyllium (15g daily) taken with 8-10 ounces of fluid can be used, though evidence quality is lower than for PEG. 1, 3
• Milk of magnesia (1 oz twice daily) is an inexpensive osmotic alternative, but avoid if you have any kidney problems. 1, 3

Important Caveats and Red Flags

Before starting treatment, ensure you do not have:

• Severe abdominal pain or distension (could indicate bowel obstruction). 1
• Blood in stools, unintentional weight loss, or anemia (these are alarm features requiring medical evaluation). 1
• Severe kidney disease (avoid magnesium-based laxatives in this case). 1, 3

If constipation persists beyond one week despite PEG use, you should seek medical evaluation to rule out fecal impaction or bowel obstruction. 3 At that point, suppositories or enemas may be needed. 3

Dosing Algorithm

1. Start: PEG 17g in 8 oz water once daily. 1
2. If insufficient after 2-3 days: Add bisacodyl 5-10mg or glycerin suppository. 1, 3
3. If still inadequate: Consider increasing PEG frequency to twice daily (17g twice daily has been studied safely). 1
4. If no response after one week: Seek medical evaluation for possible impaction or other causes. 3

The standard 17g daily dose costs approximately $1 or less per day, making it highly cost-effective. 1 Higher doses (up to 68g) have been studied for more rapid relief within 24 hours and are safe, though this is beyond typical over-the-counter recommendations. 4