<s>[INST] My three year old daughter has had severe constipation problems almost since birth to the point of popping a blood vessel in her eye at 6 months old. Her pediatrician had me put her on miralax for almost 2 years now and it seems ineffective at this point. Any suggestions? Anything I should be having her tested for at this point? The pediatrician tells me this is normal for children but I feel the process of going to the bathroom daily should not be so difficult for her. [/INST] Hi there, Thanks for using Chat Doctor. The most common cause of constipation in a kid is functional constipation. It is usually due to poor toilet training. But since your daughter is having constipation since birth, organic causes should be ruled out. The two causes that are to be looked in to are Hirschsprung disease and hypothyroidism. In Hirschsprung disease the nerve development of the bowel is affected causing constipation. Barium X-rays and anorectal manometry may be done to confirm it. In hypothyroidism, the blood levels of the thyroid hormone required for good bowel movements is low causing constipation. Blood test to check thyroid hormone levels may be done. Is this answer helpful? </s>