leis0509, I also have been diagnosed with both UC and AS. I can sympathize, I was diagnosed with UC almost a year ago, which led to the diagnosis of my AS shortly after. Getting both diagnosis within a very short period of time was very hard. I was dealing with back pain long before the UC surfaced (about
10 years), but the doctors weren't able to diagnose it as AS until they started to look at it from an auto-immune vantage point instead of a structural/skeletal problem (there is no sign of fusion as of yet, but I've had severe inflammation in my sacroiliac joints and along my spine).
I am currently on Lialda and Humira. The Humira has all but eliminated my AS symptoms completely, it's turned out ot be an excellent form of treatment. The Lialda worked fairly well at keeping my UC under control, minus some minor symptoms here and there. However.... shortly before starting the Humira (about six weeks ago) I started another flare with my UC, and have been dealing with it ever since. I don't have any personal experience with Remicade or Enbrel, but from what I understand they work through a similar mechanism as Humira (tnf-inhibitor) which is supposed to benefit both UC and AS. I've researched both conditions as well as treatments fairly extensively and from what I've found, at least from reading people's personal experiences, is that Humira may work a bit better for AS than UC. But I've also seen where Remicade sounds like it may work better for UC than Humira. Everyone's different though. I've been in contact with my GI doc and unless the UC subsides fairly soon with the Humira, my next step is Prednisone as well.