From the FDA Drug Label
Adults 12 yrs. & older 1 packet in 8 oz of liquid at the first sign of irregularity. For a lighter flavor experience and thinner drink, use more water. New Users:Start with 1 dose per day; gradually increase to 3 doses per day as necessary.
The first line medication to prevent constipation in teens is psyllium (PO), with a recommended dose of 1 packet in 8 oz of liquid at the first sign of irregularity, up to 3 times daily 1.
- Key considerations:
- Start with 1 dose per day and gradually increase as necessary
- Use at least 8 ounces of water or other fluid
- Stir briskly and drink promptly to avoid thickening
- Consult a doctor for children under 12 years old.
From the Research
For preventing constipation in teenagers, the first-line medication approach typically involves an osmotic laxative such as polyethylene glycol (PEG 3350, commonly known as MiraLAX). The standard dosage is 17 grams (about 1 tablespoon) dissolved in 8 ounces of water or juice once daily. This medication works by drawing water into the intestines, softening stool and making it easier to pass. PEG is generally safe for daily use, has minimal side effects, and doesn't cause dependence, as supported by a systematic review published in 2021 2.
Before starting medication, teens should first try lifestyle modifications including:
- Increased fluid intake (at least 8 glasses of water daily)
- Consuming more dietary fiber (25-30 grams daily from fruits, vegetables, and whole grains)
- Regular physical activity
- Establishing consistent bathroom habits
If constipation persists after 2 weeks of PEG use or worsens, medical evaluation is recommended. For occasional use, other options include magnesium hydroxide (Milk of Magnesia) or docusate sodium (Colace), but these aren't typically recommended for long-term prevention. The goal of treatment is to establish regular, comfortable bowel movements while addressing underlying causes of constipation. A study from 2016 also found that polyethylene glycol with or without electrolytes is more efficacious than placebo for the treatment of functional constipation, either in adults or in pediatric patients, with great safety and tolerability 3. Additionally, a meta-analysis from 2010 concluded that Polyethylene Glycol should be used in preference to Lactulose in the treatment of Chronic Constipation 4.
It's worth noting that while other studies have explored different regimens and combinations, such as the use of polyethylene glycol plus ascorbic acid for same-day bowel cleansing in constipated patients 5, the primary recommendation for first-line treatment remains focused on polyethylene glycol due to its efficacy, safety, and minimal side effects, as consistently supported by the most recent and highest quality evidence 2.