I have a child that is four years old currently and has had problems with BM since he was born, he will not go for a week or more at a time, when he goes the BM is huge, he was put on different meds to try to over come this issue, the medications were- Lactulose 10 gm/15ml solution twice a day for a year andhe was recently put on polyethylene glycol 3350 powder 1/2 a capful with juice as needed daily, neither of these have done anything but given him wet farts and the runs still has not had a BM, he cries and screams and is in horrible pain. What can you do about this? Who do you see? What kind of doctor? It is not normal for him to be going through this especially for this long.