I'm not sure what test they did so I can only assume its the ANA test. I don't know how often it comes up or if it does in UC. I know a lot of symptoms can overlap, I actually had a colitis episode from my lupus but its now healed.
Lupus is a very complex disease. No two people will have the exact same course of it. There are 11 criteria and you need 4 to diagnose (if you go to the Lupus main menu forum area and look under resources you can see (I can see if I can find it to link it). Even then its tricky because I believe you have to have all 4 at the same time or evidence and they cannot be caused by other things. A good source of the different symptoms and treatments is lupus.org. It explains how each symptom can effect the different parts of the body. Browsing the forum here also can give you a sense of how things can be.
Keep in mind though that lupus can be very mild for one person and the opposite for another.
DX:SLE, Sjogrens, Raynauds, Migraines, Occipital Neuralgia, Morphea (Localized Scleroderma), Iron Deficiency Anemia, IBS, Diverticulosis
Meds:Prednisone, Plaquenil, Sulindac, Tramadol, Topamax, Xanax, Imitrex, Fiorinal, Prenatal Multi, B12, Vit E, Calcium, Fish Oil, Biotin, Ferrous Gluconate, Baby Aspirin