What is the recommended dose of Pegclear (polyethylene glycol 3350) for constipation relief in adults and children, and for bowel preparation?

Dosing of Pegclear (Polyethylene Glycol 3350)

For adults with chronic constipation, use 17 grams of PEG 3350 once daily mixed in 4–8 ounces of liquid; for children undergoing bowel preparation before colonoscopy, use 1.5 g/kg/day for 4 days (maximum 100 g/day). 1

Adult Dosing for Constipation

Standard dose: 17 grams once daily, dissolved in a minimum of 4 ounces (preferably 8 ounces) of any beverage including water, juice, soda, coffee, or tea. 1

• Continue therapy for at least 1–2 weeks to achieve optimal effect, as bowel movements typically occur within 2–4 days of initiation. 1
• The therapeutic response is durable for up to 6 months, supporting long-term maintenance therapy when clinically indicated. 1

Dose Titration for Inadequate Response

If the standard 17 g daily dose is insufficient after 2 weeks of optimal dosing with adequate hydration, increase the dose (e.g., to 34 g daily) based on individual response. 1

Critical pitfall: Insufficient liquid volume is a common cause of treatment failure—patients must maintain adequate daily fluid intake throughout the day beyond just the mixing liquid. 1

Adding Stimulant Laxatives

For persistent constipation after 3–4 days of optimal PEG therapy, add a stimulant laxative (senna 8.6–17.2 mg daily or bisacodyl 5–10 mg daily) to exploit complementary mechanisms—PEG softens stool osmotically while stimulants enhance colonic motility. 1, 2

Pediatric Dosing

For Bowel Preparation Before Colonoscopy

Standard regimen: 1.5 g/kg/day for 4 days before the procedure (maximum 100 g/day), with a clear liquid diet on the fourth day, sometimes combined with an enema. 3

• Alternative 1-day preparation regimens using PEG 3350 have also been effective, though controlled trials in children are lacking. 3
• In a retrospective review of 272 pediatric patients, a 1-day PEG 3350 regimen achieved adequate bowel preparation in 93% of cases. 4

Clinical markers of adequate preparation: ≥5 stools per day and liquid stool consistency in the last 2 days of preparation predict adequate colon cleansing with 91–95% positive predictive value. 5

For Chronic Constipation in Infants and Toddlers

Start at 1 g/kg body weight/day and adjust to yield 1–2 soft, painless stools daily. 6

• Mean effective short-term dose: 1.1 g/kg/day; mean long-term dose: 0.8 g/kg/day. 6
• Constipation was relieved in 85% with short-term therapy and 91% with long-term therapy in children <2 years of age. 6

Efficacy Data

PEG 3350 at 17 g daily increases complete spontaneous bowel movements by approximately 2.9 per week compared with placebo. 1

• Increases total spontaneous bowel movements by approximately 2.3 per week versus placebo. 1
• 312 additional patients per 1,000 achieve responder criteria (≥3 spontaneous bowel movements per week) compared with placebo. 1
• 454 additional patients per 1,000 report global symptom relief compared with placebo. 1
• Treatment success (relief of constipation criteria for ≥50% of treatment weeks) occurs in 52% of patients versus 11% with placebo. 1

Safety Profile

Common adverse effects include abdominal distension, bloating, cramping, flatulence, and nausea—typically mild to moderate in severity. 1

• Diarrhea occurs in 158 additional patients per 1,000 compared with placebo. 1
• Long-term administration up to 52 weeks maintains efficacy and tolerability without clinically significant changes in electrolytes, calcium, glucose, BUN, creatinine, or serum osmolality. 1, 7
• Monthly laboratory monitoring over 6-month studies revealed no abnormal hematology, chemistry, or urinalysis findings. 1

Special Populations

Pregnancy

PEG-ELS is FDA pregnancy category C; low doses were reported safe in 225 pregnant patients treated for constipation. 3

• Tap water enemas are recommended by the American Gastroenterological Association for lower endoscopy during pregnancy, as full colonoscopy is rarely indicated. 3

After Bariatric Surgery

Patients with restrictive gastric surgery should use low-volume preparations, or extend timelines for ingestion if using high-volume preparations. 3

• Advise patients to consume sugar-free drinks and liquid foods to avoid dumping syndrome from high sugar content. 3