It's very normal anywhere up to six weeks. I've had two illeostomy surgeries s nd both times the same. You had to remember the stitches will take longer to heal a around your stoma than say one on your tummy as your removing a bag from it all the time, stool can leak unknowingly and of course when you clean you wipe near it. I wouldn't be worried because its not usual you'd have stitches and then hang some thing from them.
I would suggest emptying more often, keeping the area nice a nd clean and try not to remove your bag if not needed this will give it a chance to heal.
I wish you the best of luck