Low blood platelet disorder. 4 month old, Please Help!!!?

My nephew has been in the hospital for three weeks now and the doctors do not know what is wrong with him! He is 4 months old and his blood platelet count keeps dropping after blood transfusions. all of his organs are fine, including his bone marrow. But his body is eating his own blood platelet cells too fast for the marrow to produce enough, which is why it is low. I know this sounds like Thrombocytopenia or ITP, but unfortunately my nephew did not respond to treatment for that disease, so they crossed it out. He is also havins on his skin like Thrombocytopenia and bleeds out of his rectum when he goes to the bathroom, which is also a sign of Thrombocytopenia. But that is not what it is. So now the doctors are giving up and do not know what else to do! I am trying to reach out to everybody and anybody that might be able to know something . . . anything! Please help me. he is only four months old and doesn't deserve this torture. Doctors are definitly no help.