How do astronauts use the bathroom in space?

Cartoon illustration of an astronaut sitting on a toilet while in space. .

"Do it in the suit."

Those were the disconcerting words that the first American in space, Alan Shepherd, heard on May 5, 1961, when he advised the launch pad team he needed to urinate. Shepherd did as instructed, urinating in his spacesuit, short-circuiting his electronic biosensors. 

Shepherd's spacesuit hadn't been outfitted with a urine collection system because his mission had not been expected to last long enough for him to need to urinate.