The importance of topical metronidazole in the treatment of acute anal fissure: a double-blind study controlled for prospective randomization

PURPOSE: Acute anal fissure, a disease characterized by severe pain in the anorectal area, reduces quality of life and becomes chronic absent appropriate treatment. More recently, anaerobic infections have been noted as contributive to etiopathogenesis. This study investigates topical metronidazole’s effect in the treatment of acute anal fissure. METHODS: Our prospective randomized controlled double-blind study included 2 groups of 100 patients older than 18 years from our General Surgery Clinic with anal fissure complaints for less than 8 weeks. Topical diltiazem treatment was started in group 1, and topical diltiazem and metronidazole treatment in group 2. Pain levels were evaluated by the visual analogue scale (VAS) score, and recovery status was evaluated by physical examination findings ab initio and at the 1st, 4th, and 6th weeks. VAS score levels, demographic, clinical, and recovery status were then compared. RESULTS: There was no difference between the groups as to age, sex, pain on defecation, bleeding, constipation, and duration of pain, bleeding and constipation (P>0.05). From week 1, fissure epithelialization and healing rates were higher in group 2 (P<0.001); group 2 VAS score levels were lower than in group 1 (P<0.001) and achieved by group 1 only in week 4 (P=0.073). CONCLUSION: Adding topical metronidazole to treatment reduces the duration and severity of pain, shortens healing time, and increases the healing rate.