When I have to go it feels like pressure down below and maybe a little bloated feeling from the gas. I can hold it for however long I like though. For example the other day I was up in the mountains fly fishing and had just put my waders on and made it to the middle of the stream when I realized I had to go! Instead of going to the bathroom right away I continued to fish for a few hours untill I had waded upstream to the next set of restrooms at a campground. Not once was I afraid I was going to fill my waders from the inside!