It sounds like maybe your ostomy area may not be cleaned well enough, or you may have gotten lotion or conditioner on the area. When you clean the area, use Dial White or Ivory. First, use adhesive remover wipes, making sure you get all buildup of adhesive and barrier wipes off. Barrier wipes tend to build up, which is why I no longer use them. After removing the adhesive, take a soapy wet paper towel or washcloth and clean up the area, then wipe with plain water a few times with more paper towels or another clean washcloth. Pat dry. Put your barrier ring around the hole on the bag instead of around your stoma, making sure it's exactly on the edges of the hole of the bag. If you don't like Brava rings, Hollister makes Adapt and Cera rings that are much better. Also, is your stoma flat, or does it stick out in your bag? If your stoma is flush or flat, you will need a bag with convexity.
Be careful about anything like hand lotion or conditioners getting on your stoma area. It will cause the bags to leak or loosen your seal.
I stopped using barrier wipes as I found they are not needed unless I get irritated; then I might use Cavilon until I clear up. I use a one-piece bag, and I like it much better.