When I was somewhere between 4 and 7 years old I had a circumcision. I don't really think it is connected to POIS but it was an odd experience. For about 7-10 days afterwards I had to wear bandages around my genitals and everytime I had to pee it was a hassle and very very painful. Still don't know if this is a normal healing reaction after such a procedure, but the way I remember it (not sure what actually happened) there might have been some complications. I was often wondering if it could have caused some nerve damage and relates in some way to POIS though it seems unlikely.