Obviously whatever brand you're using isn't sticking very well. You should be able to get a shower with your appliance on and have no problems at all. In fact, you should be able to enjoy a bath or hot tub without problems, not to mention a swimming pool or the ocean.
You may want to try and figure out why it's not sticking well. Do you use a skin barrier? What brand do you use, you may want to switch, the tape may be stronger. You may want to use water proof tape around the edges of your flange.
It's not "normal" for an appliance not to hold up for a shower. It's time to change something. It may be as simple as you having oily skin under the flange. I always clean my skin under the flange (in the shower on change days) with an antibacterial soap that has the tendency to dry it out a little. This cuts back on the oils in your skin and helps prevent things from growing under there.
49 years old, CD since I was a child.
Six resection surgeries, permanent ostomy, adverse reactions to Remicade, finally off of Prednisone, hoping for a long remission from this last surgery.