While I don't claim to have a vast knowledge, I'll share what I do know.
I know that in the US that the mesalamine enemas are called Rowasa, which I use. They have worked great for me, but I have learned not to taper too quickly. I suppose there's a generic one but I get the name brand, and from what I've read, some people notice a difference, some don't but since the name brand works for me, I'll just stick with it.
Some say that the enemas 'skip over' the inflammation in the rectum, so they use suppositories too. I don't do this since just the enemas worked for me but this is something you can keep in the back of your mind if you use the enemas first.
And yes, there are steriod enemas but as I've not used them I know nothing about them, I'll leave that for someone else.
I hope you can find some relief.