The veteran stage performer was drinking water ahead of a show to keep her voice hydrated so she could play Elphaba - but she struggled to keep her composure when a fellow cast member made a mis-step and accidentally relieved herself onstage.
During an appearance on U.S. chat show The Talk on Tuesday (06Mar12), she said, "You're drinking a lot of water because you're singing eight shows a week and you're always trying to keep your voice moist...
"And when you're doing eight shows a week you're always looking for something to change it up and keep it fresh. So god forbid, somebody trips or they say a wrong word or something happens... (I start) peeing in my pants. Luckily I have a black beautiful corset dress on and I have somebody who helps me change after I get off stage."
However, Menzel is able to laugh about the incident now, insisting, "I'm not that ashamed of it. We Menzel girls just have weak bladders. My mum always jokes that when she jogs she has to be careful."