BACKGROUND In recent years, a plethora of therapeutic agents for ulcerative colitis (UC), especially novel biologics (Bio), have become available. Although it is now possible to use biological drugs, there should be no need for frequently changing medications. To avoid first-pass metabolism in the liver, thus reducing systemic bioavailability, budesonide foam has been applied as a topical steroid. We therefore evaluated whether budesonide foam has therapeutic value in UC patients who responded inadequately to Bio or to tacrolimus. MATERIAL AND METHODS We enrolled 10 patients who were experiencing an inadequate response to Bio (n=7) or to tacrolimus (n=3) at Juntendo University. We used Lichtiger's index to assess UC activity and clinical response. RESULTS Of the study patients, 4 were receiving adalimumab, 3 golimumab, and 3 tacrolimus. The average Lichtiger's index before budesonide administration was 7.1 (range 13-3), which improved to 3.4 (range 7-0) after budesonide therapy (p=0.01). Notably, 4 of the 6 cases with a Lichtiger's index >4 before budesonide administration achieved improvement of ≥3 points or remission. CONCLUSIONS Although the number of patients was small, budesonide foam had significant efficacy when added to the treatment of patients having an inadequate response to Bio or to tacrolimus. These results suggest that in cases responding poorly to Bio, adding budesonide foam as combination therapy can achieve a clinical remission.