my son is 4yrs old, he has a surgry about hirschsprung disease, already 7 months, but after surgry 7 months he still not going to poop normal, like he dont have bowmovemen. not at all . he trying to push his face is red, but his rectum is not open like he dont know how to open or even he can not relaxe him self to open. my question is why he is not getting better.