I also have an adult problem with both bowel and bladder control. I have a lifelong problem with irritable bowels. Now that I am 73 years old, my bladder "ain't like it was when it used to be."
I have a different fetish--balloons or anything inflatable. The diapers also allow me to indulge that without messing my pants. The Saddle Roll exercise balls/balloons, with their luscious curves, are especially attractive--even, occasionally, to pop. Unfortunately, my small budget severely limits that. I am always on the lookout for discounts, with little success