Hopefully you can see pretty easily that there are hundreds and hundreds of clinical trials taking place at any point in time with regards to ulcerative colitis, and although all of them might not be interesting for you, certainly there will be a few that are right up your alley.
Also, definitely realize that many of the clinical trials offer some form of compensation for your services and time. It is a definite commitment, and some of these trials can go on for several weeks, maybe even months, or possibly years, so you are a very valuable resource and they want to treat you well, and you should demand that too.
The website is clinicaltrials.gov
Good luck to all of you, and have a great week coming up!