Whatever you use for him, try it well in advance of the trip. www.abaip.com has a good, absorbent pull-up, and pads to use with it to extend the absorbency, too. I purchase my diapers (Molicare) from this site; it's a reliable supplier of incontinent needs. I've also used www.hdis.com, and you can also call them on their toll free number, 1-800-2my-home.