5yr old has chronic diahrea that eats away skin

[Unregistered]

hi....i have a 5 year old son who has severe chronic diahrea...as the doctors call it. he eats thru a feeding tube so his stool will always be loose unless he gets constipated. but when he does have a sool it is soooo acidic that it eats away his skin. it gets sooo bad that it drips with blood...not the stool but the anal area where the stool is and its basically and open flesh wound. sometimes i have to change his diaper every minute and even if he just has gas.....the fluids that come out are acidic. this has been going on for 4 years now. its become very tiresome and stressfull and really interferres with his daily life. there is time he can go to schoolo cause his but is soooo bad i cant get him in a car seat. the only thing i can put on him is ilex creme. ive tried like 100 differant barriers to protect his but t...nothing works...they seem to burn away the skin that is already sensitive .
he was tested for allergies for cow milk and is allergic to it. but he still has the problem.
if anyone has any ideas or suggestions i will be happy to hear them!!!
very desperate!!! the doctors dont have answers....its almost as if hes the only one with this problem!!!!
please help!!!!!!!!!!!!!!