About 13 years ago (God was it that long ago!) I played Hero in a community theatre production of "Forum" -- and one night we had a "bathroom" mishap.
There is a point in Act One where Pseudolus calls to Lycus, who then enters from offstage. Well, this particular night, Pseudolus called for him, and he didn't enter. So Pseudolus called again, still with no response. Luckily the actor playing Pseudolus was a seasoned pro, so he adlibbed long enough until Lycus finally made his entrance.
It turned out that the actor playing Lycus had some sort of "stomach virus" (as he called it -- but it was probably just some bad Taco Bell) and was still on the john when it was time for his entrance cue. When he entered, he played it up by having a sheet of toilet paper attached to his sandals. The audience roared with laughter at this, and the show continued on without a hitch. Luckily with the slapstick nature of the show, most of the audience assumed that it was a pre-planned gag.
"You pile up enough tomorrows, and you'll find you are left with nothing but a lot of empty yesterdays. I don't know about you, but I'd like to make today worth remembering." --Harold Hill from The Music Man