The Effect of Medical Treatment on Patients with Fistulizing Crohn's Disease: A Retrospective Study

Background Fistulas are a major complication of Crohn's disease (CD), but the treatment strategy for fistulizing Crohn's disease is controversial. The aim of this study is to analyze the efficacy of medical therapy for fistulizing Crohn's disease. Methods Therapeutic regimens and clinical outcome of medical therapy were evaluated in 10 patients with fistulizing Crohn's disease (6 with external fistulas, 4 with internal fistulas). Complete response was defined as fistula closure with complete arrest of drainage in cases of external fistula, and disappearance of the fistula demonstrated by imaging studies in cases of internal fistula. Clinical remission was defined as a Crohn's disease activity index of less than 150 points. Results Complete responses were observed in all 6 patients with external fistulas (4 patients treated with a combination of antibiotics and immunomodulators, and 2 also treated with infliximab). In contrast, fistula closure was observed in only 1 of 4 patients with internal fistulas. Clinical remission of CD was achieved in all patients with external fistulas, whereas there was no significant difference in the CD activity index before and after medical therapy in patients with internal fistulas. Conclusions External fistulas were more responsive to medical therapy than internal fistulas in patients with CD. Combined treatment with antibiotics and immunomodulators might be a suitable initial therapy for CD patients with external fistulas, and infliximab can be used as an additional therapy in cases refractory to this combination therapy. However, randomized controlled studies will be required to investigate what kinds of therapies are optimal for CD patients with fistulas.