What causes bladder wall thickening in children? I have a 9 year olds son, who has had a US, MRI, VCUG, Urodynamics and we can get an answer of why he has this. he has recurrent UTI's not a whole lot about 4 in a year. he is unablet to control his bladder his wall is 9mm thick. We r waiting on a scope now, so I am just trying to figure out what could be causing all this. Thanks