Comparison of rectal diclofenac suppository with injectable tramadol for postoperative pain management in adult fistula-in-ano surgery: a randomized controlled trial

Managing pain after surgery is vital for recovery and patient satisfaction, particularly after anorectal procedures. Fistula in ano surgery is especially painful due to the dense nerve supply in the anal canal below the dentate line. This study compared the effectiveness and safety of rectal diclofenac, a nonsteroidal anti-inflammatory drug (NSAID), and intramuscular tramadol in an adult Indian population. A prospective, randomized controlled trial was conducted with 60 adult patients (ASA I–II) who underwent elective fistula in ano surgery at a tertiary care center. Patients were randomly assigned to Group A (100 mg rectal diclofenac suppository immediately after surgery) or Group B (50 mg intramuscular tramadol every 8 h) using a computer-generated sequence. Both groups received 1 g of intravenous paracetamol every 8 h for background pain relief. The primary outcome was pain intensity measured using the Visual Analog Scale (VAS) at 1, 6, 12, and 24 h. Secondary outcomes included the need for rescue pain relief (triggered at VAS > 5 using IV Fentanyl 0.5 µg/kg bolus), occurrence of side effects (nausea, vomiting, allergic reactions, renal dysfunction), and stability of vital signs. Data were analyzed using the appropriate statistical software, with significance levels set at p < 0.05. Baseline demographics, including age, sex, and weight, were similar between the two groups. VAS scores were similar at 1 h (4.56 ± 1.03 vs. 4.87 ± 1.50, p = 0.76) and 24 h (1.63 ± 0.49 vs. 1.97 ± 0.76, p = 0.34). However, Group A demonstrated a clinically meaningful trend toward lower pain scores at 6 h (3.37 ± 0.72 vs. 5.73 ± 1.34, p = 0.03) and significantly lower pain scores at 12 h (1.57 ± 0.83 vs. 3.77 ± 0.94, p = 0.01) after Bonferroni correction. The need for rescue pain relief was lower in the diclofenac group (6.7% vs. 23.3%). Nausea was significantly more common in Group B (33.3%) than in Group A (6.7%, p = 0.01). Both groups maintained stable vital signs. Rectal diclofenac offers better analgesia in the intermediate phase and better tolerability than intramuscular tramadol for fistula-in-ano surgery. These findings support its role as an effective component in multimodal postoperative analgesia.