How can I fix water leaking from the area where you actually turn off the water supply behind the toilet?

Is it leaking from the stem of the angle stop? Please describe the leak so that we can tell exactly where, and what's, leaking. Regards. Tom

I think it just needs a washer. It is leaking at the knob to turn the water on and off.

Hi Ed and welcome to The Plumbing Page at AskMeHelpDesk.com You are responding to a 4 year old dead thread. Please check the date before you post. Thanks, Tom