Interested in a particular medical field of study

I've been goggling trying to find a particular field of study, which name is alluding me. I'm trying to find research into body modifications. Altering the human body to do things it was either not intended to do, or an individual was not born with the predisposition for (such as hypermobility AKA double jointed). While I can find research into replacing bones with metal alloys I'm hoping to find an overarching field of study.

On a second note a co-worker and I were talking and the question came up. "With all of the history of our world and medical science and this one important question that has loomed over every generation. How is it that no one has discovered how to 'honestly' increase a mans penis size" referring to surgical or otherwise. Lots of lies and speculations out there, but no definitive answer for an obvious popular field of study.

I look forward to your answers (yup I know this is an odd place to ask, but this is the "off-topic" area :) )