I could not use the barrier rings because they just didn't work on me! So, I use a skin barrier that I really love. I've tried several other skin barrier liquids/wipes/etc., but this is the only thing that works: Coloplast Prep Skin Protector Roll-on. My insurance sends me two per month, but I can rarely get through one bottle.
I also use Adapt Paste around the opening, then apply to ostomy. The paste works for me, but the barrier rings never did work for me. Also, I find that I sometimes need to change the ostomy bag every one or two days, depending on skin irritation. If it is irritated, I change it more often so it can heal. Once it's healed, I can go back to every 3 days. The hospital nurse said the average is every 3 days.