This study evaluated the efficacy and safety of infliximab, a chimeric monoclonal antibody against tumor necrosis factor α, in treating fistulas in patients with Crohn's disease. A randomized, multicenter, double-blind, placebo-controlled trial was conducted with 94 adult patients who had draining abdominal or perianal fistulas lasting at least three months. Patients were randomly assigned to receive either placebo, 5 mg of infliximab per kilogram, or 10 mg of infliximab per kilogram, administered intravenously at weeks 0, 2, and 6. The primary endpoint was a reduction of 50% or more in the number of draining fistulas observed at two or more consecutive study visits. Secondary endpoints included the closure of all fistulas. Results showed that 68% of patients receiving 5 mg of infliximab per kilogram and 56% of those receiving 10 mg per kilogram achieved the primary endpoint, compared to 26% in the placebo group. Additionally, 55% of patients receiving 5 mg of infliximab per kilogram and 38% of those receiving 10 mg per kilogram had all fistulas closed, compared to 13% in the placebo group. The median duration of fistula closure was three months. Adverse events were common in all groups, with headache, abscess, upper respiratory tract infection, and fatigue being the most frequent. The study concluded that infliximab is an effective treatment for fistulas in patients with Crohn's disease, with a recommended initial dose of 5 mg per kilogram followed by identical doses at weeks 2 and 6.This study evaluated the efficacy and safety of infliximab, a chimeric monoclonal antibody against tumor necrosis factor α, in treating fistulas in patients with Crohn's disease. A randomized, multicenter, double-blind, placebo-controlled trial was conducted with 94 adult patients who had draining abdominal or perianal fistulas lasting at least three months. Patients were randomly assigned to receive either placebo, 5 mg of infliximab per kilogram, or 10 mg of infliximab per kilogram, administered intravenously at weeks 0, 2, and 6. The primary endpoint was a reduction of 50% or more in the number of draining fistulas observed at two or more consecutive study visits. Secondary endpoints included the closure of all fistulas. Results showed that 68% of patients receiving 5 mg of infliximab per kilogram and 56% of those receiving 10 mg per kilogram achieved the primary endpoint, compared to 26% in the placebo group. Additionally, 55% of patients receiving 5 mg of infliximab per kilogram and 38% of those receiving 10 mg per kilogram had all fistulas closed, compared to 13% in the placebo group. The median duration of fistula closure was three months. Adverse events were common in all groups, with headache, abscess, upper respiratory tract infection, and fatigue being the most frequent. The study concluded that infliximab is an effective treatment for fistulas in patients with Crohn's disease, with a recommended initial dose of 5 mg per kilogram followed by identical doses at weeks 2 and 6.