The Sims Online:
Bladder

Another easy thing to understand - you have to pee every once in a while! They were nice in the on line version of the game and assume that every toilet is in a "stall". So multiple people can use toilets in the same room, and you don't have to shoo people out before you use it. Yes, you are fuzzed out while you use the toilet. Be sure to use one when you get into the red area, so that you don't end up with an embarassing puddle!

The Sims Online Tips, Techniques and Walkthroughs