The role of topical therapy for perianal fistulizing Crohn's disease: are we forgetting something?

Introduction: Rectal inflammation is the principal risk factor for the development of perianal fistulizing Crohn's disease. However, no topical therapy direct to rectal healing is discussed in European' guidelines. The aim of this systematic review was to evaluate the role of topical therapy in healing the rectal inflammation in Crohn's disease.
Evidence Acquisition: A MEDLINE search of all studies published in English until December 2018 was conducted. Articles were identified using the strings "Crohn's disease and topical therapy" or "perianal Crohn's disease and topical therapy."
Evidence Synthesis: Contradictory results about the efficacy of topical metronidazole were present. No benefit from topical tacrolimus use was demonstrated. Mesalazine suppositories induced and maintained remission of rectal inflammation in 50% of patients with rectal Crohn's disease. Few data were available about the role of local therapy for the fistulous tract in Crohn's disease. Local mesenchymal stem cells therapy could be a promising new approach.
Conclusions: Due to the disappoint success rate of current strategy in perianal fistulizing Crohn's disease, the role of rectal inflammation as a causative factor and the fair success rate of topical therapy with mesalazine suppositories in the healing of rectal inflammation without relevant side effects, more studies are advisable in this field.