Sasquatch's reply is very good and right on...
I am very allergic to some of the adhesives which was a problem until that was resolved.
I did find a way of getting the healing of the skin to speed up. I left the stoma open while laying flat in the tub in a few inches of really warm water. I flooded the stoma area with the water and let it evaporate several times for about an hour. It really moved things along - I am very careful to immediately remove a bag if it itches -- that is a guarantee there is a problem that needs to be addressed. I do know that for me I was not cutting the bag opening small enough for awhile as I had reduced in size just enough that the base was getting attacked by acid. I healed and then a specialist had me change to the convex pouch which miraculously was the end of the issue at least for now -- what a relief!!