Having had an ileostomy for 50 years, I believe I've tried just about every skin barrier product known to man. My skin is allergic to almost everything except water. I also have a burst appendix scar above my stoma and a hernia to the right of my stoma.
For me the best skin barrier product is one made by Hollister (hollister.com). I wear their appliance for at least a week and usually for up to 10 days. And yes, I shower daily. I know this wear time is not recommended, but it works for me.
Before applying the appliance I put a slim O-ring over my stoma. When applying the appliance I hold it on the skin for approximately 60 seconds and then window tape it with a silicone water proof tape. Every tape I have tried eventually ended up irritating my skin, except for this silicone water proof tape.
Following on the products, mentioned above, that I use. Go to Hollister's web site for more product and description information. I hope this is of some help.