Mair,

Instead of going the adult diaper route, I bought highly absorbable and washable pad for my dad. This one absorbs 1800cc's

http://www.amazon.com/Reusable-Bedpa.../dp/B0002DMPFS

I also bought chair covers in a light blue velour for his living room chair.

Dad had had a stoke and had severe diabetes and couldn't move quickly. Still, I think it beats wearing a diaper. Mom had the pad under the sheet on Daddy's side of the bed.

As far as how often this will happen to you, I think that gets back to "your MS is your MS" and it isn't easy to know.

My best to you,
ANN