What brand are you using? I am using Convatec and had Hollister in the past and I went swimming in the hotel pool and hot tub and had no problems other than a shortened lifespan. I usually get 5 or 6 days on the flange, and using the pool they may last 4 days.
I don't shower everyday, I try to lean forward and avoid the area but I do give the bag and area a quick soap and rinse.