Flaxseed (Linum usitatissimum) has been used both traditionally and more recently with scientific interest for managing constipation, including in children. Flaxseed is rich in dietary fiber—both soluble and insoluble—and contains mucilage, which can increase stool bulk and improve intestinal motility. Several clinical studies in adults have shown that flaxseed supplementation can improve bowel movement frequency and stool consistency in cases of mild to moderate constipation. The mechanism is primarily through increasing stool bulk and water content, making stools easier to pass.

Evidence in children, however, is more limited. Some small-scale studies and case reports suggest that flaxseed can be effective and well-tolerated in pediatric constipation, especially for children who do not respond well to standard treatments like polyethylene glycol or lactulose. A 2018 randomized controlled trial in children with functional constipation found that flaxseed oil improved stool frequency and consistency. However, these studies are relatively few, with small sample sizes and short durations.

Overall, while the scientific evidence supporting flaxseed’s use for constipation in children is promising, it is not yet robust or extensive. Larger, high-quality clinical trials are needed to establish safety, dosage, and efficacy in pediatric populations. Until then, flaxseed may be considered when standard therapies are inadequate, but should be used under medical supervision.