What is PEG 17?
PEG 17 refers to polyethylene glycol 3350 (PEG 3350) at a dose of 17 grams, which is an osmotic laxative approved by the FDA for treating occasional constipation and widely used for chronic idiopathic constipation. 1
Mechanism and Formulation
PEG 3350 is a long-chain polymer of ethylene oxide that works as an osmotic laxative by retaining water in the stool, thereby softening it and increasing bowel movement frequency 1. The standard adult dose is 17 grams (approximately 1 heaping tablespoon) dissolved in 4-8 ounces of water, juice, soda, coffee, or tea, taken once daily 2.
Dosing for Elderly Patients with Colostomy
For your specific scenario of an elderly patient with a recent colostomy, the approach differs significantly:
Standard Constipation Management (if applicable):
- Start with 17 grams once daily mixed in 4-8 ounces of liquid 2
- Important caveat for elderly: In geriatric nursing home patients, a higher incidence of diarrhea occurred at the standard 17g dose. If diarrhea develops, discontinue PEG 3350 2
- Allow 2-4 days (48-96 hours) to produce a bowel movement 2
For Colostomy Irrigation (if that's the intent):
Use PEG 3350 with electrolytes solution instead of plain water for colostomy irrigation 3. A randomized crossover trial demonstrated that PEG electrolyte solution significantly outperformed water for colostomy irrigation with:
- Shorter total washout time (38 vs 53 minutes, P=0.01)
- Fewer leakage episodes (0.7 vs 2.3, P<0.001)
- Higher satisfaction scores (8.8 vs 5.8, P<0.001)
- Less stoma pouch usage per week 3
Efficacy and Safety Profile
The 2023 AGA-ACG guidelines give PEG a strong recommendation with moderate certainty of evidence 1. Key benefits include:
- Increases complete spontaneous bowel movements by 2.90 per week vs placebo 1
- Increases spontaneous bowel movements by 2.30 per week 1
- 42% of patients meet FDA responder criteria (vs 13% placebo) over 24 weeks 4
- Efficacy is durable for up to 6 months 1 and even 52 weeks 5
Common Side Effects:
- Bloating, flatulence, diarrhea (158 more per 1,000 vs placebo) 1
- Abdominal distension, loose stool, nausea 1
- Most events are mild to moderate 1
- Critical warning: Prolonged, frequent, or excessive use may result in electrolyte imbalance and laxative dependence 2
Key Clinical Considerations
Do NOT use PEG 3350 for more than 2 weeks without physician direction 2. The FDA approval is specifically for "occasional constipation," though clinical trials demonstrate safety and efficacy for chronic use up to 6 months 1.
Monitoring:
- No clinically significant effects on laboratory tests have been demonstrated 2
- No changes in electrolytes, calcium, glucose, BUN, creatinine, or serum osmolality in studies 6
Practical Measurement:
If using household measuring devices, a leveled tablespoon contains approximately 10 grams of PEG 3350, so nearly 2 leveled tablespoons would approximate the 17g dose 7. However, the manufacturer's cap marked to 17 grams is most accurate 2.