Never say never!
One of the fastest ways of catching the IC wannabes is whether they have a carry bag and/or a support diaper bag of size in the SUV. I always target backing into parking places (as stated above) as this provides the rear of the SUV to change when the worst occurs. And, yes, plastic pants are a life saver and another common items for IC folk - plan for the worst!
Likely because, I have long had acid reflux, my food intake is fairly bland, but even with being U-IC, BM events happen and tend to be limited to a couple of times a year for me. But hell, when they occur, commonly from food poisoning, which is jokingly call the 24 hour flu! When I traveled internationally, I eat at excellent eateries with wonderful wines and avoid tap water completely.
As stated in past Posts, I carry a briefcase (diaper bag), which was well fitted to support the worst case. Public bathroom clean-ups just plan suck, but having the need suppliers vasty eases things. Since I became U-IC shortly after the arrival of my son, first upgrading his diaper bag and later converting it to support only me, was a great help as he pre-confirmed what was needed and mine simply became an upsized version of his.
Plan for the worst and rejoice when it does not happen!!