The purpose of this pilot study is to evaluate the immunologic and clinical response to type I interferon administered to patients with ulcerative colitis. Ulcerative colitis (UC) is a chronic, relapsing inflammation of the colonic mucosa with major symptoms of diarrhea, hematochezia, abdominal pain, and an accompanying increase in colorectal carcinoma risk. Novel approaches to therapy of UC are required because the burden of disease is great (about 500,000 prevalent cases in the United States), standard medical therapy is limited in effectiveness and toxicity, and surgical therapy, albeit curative, results in permanent ostomies or complication-prone alternatives.