I was told by my daughter’s ped. and urologist that we talk about it from the start. She gets checked down there once a year by her urologist to make sure all is growing well with the rest of her body. We have talked about it at her level of understanding. Meaning, when she was old enough to understand we would say we have to check your bottom because you had surgery on it when you were a baby and we need to make sure all is ok. As she got older and older and started to ask questions we just talk to her on her level. If you go into too much detail it can confuse. Besides you loose a kid after 5 minutes. It goes along the line of talking about where babies come from. Depending on how old they are you have to keep the explanation to their understanding. Today we have talked more in lenghth about her surgery. We tell her that because her body wasn’t making the necessary "chemicals" in her body it affected her genitals. Then I go on to tell her the many birth defects that can happen with people. Something their bodies could not make, created their hands to look a certain way. And so on.  She already knows why she takes her pills daily. That started from Preschool when she didn’t understand why everyone else didn’t take pills like her. I told her some do. The people with Diabetes do because their body cannot make a chemical that is necessary to keep them healthy. I told her some people are born with poor eye sight. They need glasses to see. Some are born without the ability to walk. They use a wheel chair. She was born not able to make this chemical to help her fight off fevers and other sicknesses so we replace what her body cannot make by giving her those pills. It worked for her.