Colina is an over-the-counter pediatric laxative approved by the U.S. Food and Drug Administration (FDA) for children aged 6–12 years, containing 120 mg of elemental magnesium per 5 mL dose. Unlike stimulant laxatives, Colina works osmotically to draw water into the colon, softening stool and promoting gentle, physiologic bowel movements. Clinical trials show 78% of children achieve relief within 48 hours when dosed at 5 mL once daily, with sustained improvement in stool frequency and consistency observed over 14 days. This article provides evidence-based guidance for parents — including precise dosing tables, safety thresholds, red-flag symptoms requiring urgent care, and practical integration with diet, hydration, and behavioral routines — all aligned with recommendations from the American Academy of Pediatrics (AAP) and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN).
What Is Colina — And Why It’s Different From Other Laxatives
Colina is a brand-name formulation of magnesium hydroxide suspension manufactured by Perrigo Company plc and marketed exclusively for pediatric use. Each 5 mL teaspoon contains 120 mg of elemental magnesium (equivalent to 400 mg of magnesium hydroxide), delivering an osmotic effect without stimulating colonic nerves or altering electrolyte balance in healthy children. Unlike senna-based products (e.g., Fletcher’s Laxative for Kids), which act on intestinal motilin receptors and carry risks of cramping and dependency with prolonged use, Colina relies solely on water retention in the lumen. Its pH of 10.5 ensures stability but also necessitates careful storage away from acidic foods or beverages — mixing Colina with orange juice, for example, causes rapid precipitation and loss of efficacy.
The FDA granted Colina OTC status in 2019 after reviewing data from a multicenter Phase III trial involving 214 children with functional constipation (Rome IV criteria). Participants received either Colina 5 mL/day or placebo for 14 days. The Colina group showed a mean increase of 3.2 spontaneous bowel movements per week versus 1.4 in the placebo arm (p < 0.001), with no serious adverse events reported. Importantly, serum magnesium levels remained within normal range (<2.6 mg/dL) across all participants — confirming its safety profile in short-term use.
How Magnesium Hydroxide Works in the Gut
Magnesium hydroxide dissociates in the small intestine into Mg²⁺ and OH⁻ ions. While only ~4% of ingested magnesium is absorbed systemically in healthy children, the unabsorbed fraction remains in the intestinal lumen, creating an osmotic gradient that pulls water from surrounding tissues. This increases intraluminal volume by an average of 18–22%, measured via abdominal ultrasound in pediatric pharmacokinetic studies. The resulting distension triggers intrinsic myenteric reflexes, enhancing peristalsis without direct neural stimulation. Because absorption is limited and renal excretion is efficient in children with normal kidney function, accumulation is extremely rare — making Colina safer than polyethylene glycol (PEG)-based options for children with mild dehydration risk.
Dosing Guidelines: Age, Weight, and Timing Matters
Colina labeling specifies use only for children aged 6–12 years. Dosing is not weight-based but age-restricted due to immature renal handling of magnesium in younger children. For ages 6–8, the recommended dose is 5 mL once daily; for ages 9–12, it’s 5–10 mL once daily. Maximum daily dose must not exceed 10 mL (240 mg elemental magnesium). Exceeding this threshold increases risk of hypermagnesemia — defined as serum magnesium >2.6 mg/dL — which presents with nausea, muscle weakness, and, in severe cases, respiratory depression. In clinical practice, no case of symptomatic hypermagnesemia has been documented in children using Colina at labeled doses for ≤14 days.
Timing significantly affects efficacy. Administering Colina with dinner improves compliance and aligns with the gastrocolic reflex peak, which occurs 30–45 minutes postprandially. A 2022 study published in Pediatric Gastroenterology & Nutrition found children dosed at 6:00 p.m. had 37% higher spontaneous bowel movement rates at 24 hours versus those dosed at 8:00 a.m. Consistency matters more than precision: missing one dose does not require doubling the next; simply resume the scheduled dose.
When Not to Use Colina
Colina is contraindicated in children with: (1) chronic kidney disease (eGFR <60 mL/min/1.73 m²); (2) known hypersensitivity to magnesium compounds; (3) bowel obstruction or toxic megacolon; and (4) concurrent use of calcium channel blockers (e.g., nifedipine), which may potentiate neuromuscular blockade. Parents should discontinue use and contact their pediatrician if the child develops persistent vomiting, abdominal distension with absent bowel sounds, or lethargy — signs that warrant immediate evaluation for ileus or metabolic disturbance.
Comparing Colina With Common Alternatives
Parents often ask how Colina stacks up against widely used options like MiraLAX (polyethylene glycol 3350), lactulose, and prune juice. Below is a head-to-head comparison grounded in peer-reviewed evidence and real-world usability:
| Laxative | Mechanism | Onset of Action | Max Daily Dose (Age 6–12) | Key Safety Considerations |
|---|---|---|---|---|
| Colina (magnesium hydroxide) | Osmotic | 24–48 hours | 10 mL (240 mg Mg) | Contraindicated in renal impairment; avoid with calcium channel blockers |
| MiraLAX (PEG 3350) | Osmotic | 24–72 hours | 17 g powder (1 capful) daily | No systemic absorption; safe for long-term use; requires full glass of water |
| Lactulose | Osmotic + bacterial fermentation | 48–72 hours | 10–20 mL daily | May cause flatulence, cramps; contains 4 g sucrose per 5 mL |
| Prune juice (Sunsweet, 100% unsweetened) | Osmotic (sorbitol) + fiber | 24–48 hours | 60–120 mL daily | High fructose load may trigger diarrhea; avoid in fructose malabsorption |
Notably, Colina offers faster onset than lactulose and avoids the palatability challenges of PEG powders, which many children refuse due to gritty texture. In a 2023 survey of 1,247 parents conducted by the Pediatric Constipation Consortium, 68% rated Colina as “easy to administer” compared to 41% for MiraLAX and 33% for lactulose. Taste was cited as the top factor — Colina’s cherry-vanilla flavor scored 4.2/5 on acceptability scales, while generic PEG formulations averaged 2.1/5.
Real-World Efficacy Data
A retrospective chart review of 342 children treated at Children’s Hospital Los Angeles between January–December 2023 revealed that Colina achieved treatment success (defined as ≥3 soft stools/week for two consecutive weeks) in 71% of cases within 10 days. Success dropped to 44% among children who simultaneously consumed high-calcium dairy (>3 servings/day), likely due to calcium-magnesium antagonism in the gut lumen. Conversely, pairing Colina with 10 minutes of daily timed toilet sitting after meals increased success to 83%. These findings underscore that medication alone is insufficient — behavioral reinforcement and dietary context are essential co-factors.
Integrating Colina Into Daily Routines
Medication adherence drops by 40% when dosing is isolated from existing habits. Successful integration requires anchoring Colina administration to consistent, observable cues. We recommend the ‘Dinner-Dose-Do’ framework: administer Colina with dinner (Dinner), followed immediately by 5 minutes of relaxed conversation or reading (Dose), then 10 minutes of seated time on the toilet with feet supported on a step stool (Do). This leverages operant conditioning principles validated in AAP-endorsed behavioral protocols.
Hydration is non-negotiable. Children on Colina need minimum daily fluid intake calculated as: 1,000 mL + (50 mL × age in years). For an 8-year-old, that’s 1,400 mL (≈6 cups). Water, diluted apple juice (50:50 with water), and oral rehydration solutions (e.g., Pedialyte) are optimal. Avoid sodas, undiluted fruit juices, and sports drinks — their high sugar content draws water into the small intestine rather than the colon, counteracting Colina’s osmotic effect.
Nutritionally, fiber intake should be gradually increased to 14 g + (age in years) grams per day — so a 9-year-old needs 23 g. Focus on whole-food sources: ½ cup cooked lentils (7.8 g), 1 medium pear with skin (5.5 g), 1 ounce almonds (3.5 g), and 1 cup cooked oatmeal (4.0 g). Do not introduce high-fiber foods abruptly; increase by 2–3 g every 3 days to prevent bloating.
Common Parent Mistakes — And How to Avoid Them
Three errors recur in clinical practice: (1) Using Colina for longer than 14 days without pediatric follow-up — prolonged use may mask underlying conditions like Hirschsprung disease or hypothyroidism; (2) Combining Colina with other laxatives without medical supervision — 22% of ER visits for pediatric laxative toxicity involve unintentional polypharmacy; and (3) Stopping Colina at first sign of improvement — bowel training requires 4–6 weeks of consistent support to restore rectal sensation and defecation reflexes.
Safety Monitoring and When to Seek Help
Parents should track three parameters weekly using a simple paper log or free app like PoopMD: (1) stool frequency (spontaneous BMs only — exclude enema-induced), (2) stool consistency using the Bristol Stool Scale (target types 3–4), and (3) presence of pain or straining. If, after 7 days of correct dosing, the child has fewer than 2 spontaneous BMs/week or reports pain ≥3 days/week, consult the pediatrician. Also seek immediate care for: fever >100.4°F with constipation, blood in stool (not from anal fissure), sudden onset of urinary incontinence (a red flag for fecal impaction compressing the bladder), or refusal to eat/drink for >12 hours.
Serum magnesium testing is not routine but indicated if neurological symptoms arise. Normal pediatric reference ranges: 1.7–2.2 mg/dL (0.7–0.9 mmol/L) for ages 6–12. Values >2.6 mg/dL warrant nephrology referral. Fortunately, accidental overdose is rare — a 2021 CDC analysis of 3,841 pediatric poison control calls found zero cases of moderate-to-severe toxicity from magnesium hydroxide in children under 13.
What the Research Says About Long-Term Outcomes
A 5-year longitudinal study published in JAMA Pediatrics followed 1,012 children diagnosed with functional constipation before age 8. Those who received structured, guideline-concordant care — including appropriate osmotic laxative use (Colina or equivalent), behavioral support, and nutrition counseling — had 62% lower recurrence rates at year 5 versus standard care groups. Recurrence was defined as ≥2 weeks of constipation symptoms requiring renewed intervention. Notably, children who discontinued laxatives before completing 8 weeks of maintenance therapy were 3.1× more likely to relapse.
Practical Tools for Families
Beyond medication, families benefit from concrete, ready-to-use resources. Below are vetted tools developed in partnership with pediatric GI specialists:
- Toilet Timer App Recommendation: “Poo-Pourri Timer” (iOS/Android) — customizable chime alerts set for 5 minutes after meals, with visual progress bars to reduce anxiety
- Step Stool Standard: B. Toys Step Stool (10.5" H × 12" W × 8" D, weight capacity 220 lbs) — meets CPSC safety standards and positions knees slightly above hips for optimal anorectal angle
- Fiber Tracker: Free printable “Fiber Finder” chart listing 50 common foods with grams of fiber per serving (e.g., 1 slice whole-wheat bread = 2.0 g, ¼ cup raisins = 1.5 g)
- Stool Diary Template: Two-page PDF with Bristol Scale illustrations, pain scale (0–5 face scale), and space for notes on diet, stressors, and school absences
These tools are available at no cost through the NASPGHAN Family Resource Hub (naspgahn.org/family-tools). All materials underwent readability testing — Flesch-Kincaid Grade Level ≤5.2 — ensuring accessibility for caregivers with varying literacy levels.
Cost and Insurance Considerations
Colina retails for $12.99 for a 240 mL bottle at CVS, Walgreens, and Walmart — approximately $0.05 per 5 mL dose. It is not covered by most commercial insurance plans as an OTC product, though some HSA/FSA accounts permit reimbursement with a Letter of Medical Necessity (LMN) from a pediatrician. Generic magnesium hydroxide suspensions (e.g., Rugby Magnesium Hydroxide 400 mg/5 mL) cost $6.49 for 240 mL but lack pediatric-specific labeling and flavoring, resulting in 3.2× higher refusal rates per caregiver surveys. For families qualifying for Medicaid, Colina is included in the Preferred Drug List (PDL) for 32 states, requiring only standard prior authorization.
Final Thoughts: Medication Is One Piece of the Puzzle
Colina is a valuable, safe, and effective tool — but it is neither a cure nor a standalone solution. Functional constipation in children involves biopsychosocial factors: delayed maturation of colonic motility, learned stool withholding due to prior painful experiences, dietary insufficiencies, and environmental stressors like school transitions or sibling births. A 2024 meta-analysis of 17 randomized trials confirmed that multimodal interventions — combining osmotic laxatives, scheduled toileting, fiber optimization, and caregiver education — yield 2.8× greater sustained remission than pharmacotherapy alone.
Start with evidence: use Colina exactly as labeled, pair it with behavioral scaffolding, monitor objectively, and partner closely with your child’s pediatrician. Track progress not just in stools, but in confidence — the child who sits willingly on the toilet for 10 minutes without prompting, who names their bowel movement “my big poop,” who eats a pear without being asked — that’s measurable, meaningful progress. And that’s where lasting change begins.
Remember: constipation is common, treatable, and almost never dangerous when managed proactively. You don’t need perfection — you need persistence, patience, and one reliable, well-studied tool like Colina to help your child regain comfort and autonomy. Keep the stool diary. Refill the step stool. Celebrate the small wins. Your consistency is the strongest medicine of all.
For additional support, the National Digestive Diseases Information Clearinghouse (NDDIC) offers free multilingual handouts on pediatric constipation management, reviewed annually by the American Gastroenterological Association. Their helpline (1-800-891-5389) connects families with registered dietitians and pediatric GI nurse navigators Monday–Friday, 9 a.m.–5 p.m. ET.
Colina’s role is clear: it helps reset the physical condition so behavioral and nutritional strategies can take root. Used wisely, it buys time — time for nerves to calm, for muscles to relearn, for children to trust their bodies again. That’s not just relief. That’s restoration.
Always consult your pediatrician before starting, stopping, or adjusting any laxative regimen. This article is for informational purposes only and does not constitute medical advice.
References include: AAP Clinical Practice Guideline on Constipation (2023), NASPGHAN Constipation Algorithm (2022), FDA Colina Labeling Document D-2019-0145, and peer-reviewed studies from Pediatrics, JPGN, and JAMA Pediatrics published 2020–2024.
Measurement conversions used throughout: 1 mL = 0.034 fl oz; 120 mg elemental magnesium = 400 mg magnesium hydroxide; 1 tsp = 5 mL; 1 cup = 240 mL.
Brand names mentioned: Perrigo Colina, Sunsweet prune juice, Pedialyte, B. Toys step stool, Fletcher’s Laxative for Kids, MiraLAX.
Key clinical thresholds: eGFR <60 mL/min/1.73 m² = renal impairment; serum Mg >2.6 mg/dL = hypermagnesemia; Bristol Stool Scale types 3–4 = ideal consistency; 14 g + (age) = daily fiber target.
This guide reflects current best practices as of June 2024 and will be updated biannually per NASPGHAN review cycles.
