My son is 4 years old. And ever since he was a baby he s been suffering with painful bowel movements and constipation. He has been on miralax everyday or every other day for 3 years. And he still has difficulties more times than none. I am worried it could be something more serious. There s no bloody stools, thank goodness. He only drinks milk with carnation instant breakfast because he doesn t eat much solid food either. I wonder if after all of this he may be lactose intolerant.