Which laxative is commonly used to treat functional constipation in children?

• A. Polyethylene glycol
• B. Lactulose
• C. Bisacodyl
• D. Magnesium hydroxide

Answer: (A)

In functional constipation for children, the goal is to soften the stool and improve regular bowel movements with a laxative that is safe for long-term use. Polyethylene glycol achieves this by acting as an osmotic agent in the gut: it isn’t absorbed, so it stays in the intestinal lumen and draws water into the stool. This increases stool softness and frequency with minimal cramping or systemic side effects, making it well suited for ongoing management in kids.

This option is favored because clinical studies show polyethylene glycol reliably improves stool frequency and reduces stool withholding, with good tolerability and a favorable safety profile. Other laxatives have downsides in children: lactulose can cause gas and bloating and may be less effective; stimulant laxatives like bisacodyl can cause abdominal cramping and are usually reserved for short-term use or rescue therapy; magnesium hydroxide can risk electrolyte disturbances in some children, especially if dehydration or kidney issues are present. Hence, polyethylene glycol is typically the first-line choice for pediatric functional constipation.