My son had terrible constipation when he was younger. I also was hesitant to give him Miralax for so long. When I expressed my concerns to my Pediatrician, she told me it was safe to use. If I remember right, she also told me that people with Down's Syndrome often have the constipation issues and are put on Miralax indefinitely. My son is now 6, and we still give it to him. We miss days here and there because he is much better, but he is still on it. Good Luck!!