After Years Of Juggling Between Hospital And Physcologists Im Still

After years of juggling between hospital and physcologists im still no closer to an explaination. When my soon was around 2 he got his anus stretched twice since then he has had problems with going to the toilet he soils himself and no one seems to know whats wrong hes 11 now and gets diarrhea every 2 weeks and goes in himself he has to bring changes of clothes to school. Any suggestion would be great its affecting hos every day life