Chronic anal fissure is one of the most common benign anorectal disorders encountered in surgical practice. It is defined as a longitudinal tear in the distal anal canal, typically extending from the dentate line to the anal verge.1 The condition is associated with significant morbidity due to severe pain during and after defecation, bleeding per rectum, and fear of bowel movements, which often leads to constipation and further exacerbation of symptoms. Although it is not a life-threatening condition, chronic anal fissure has a profound impact on quality of life.2 The pathophysiology of chronic anal fissure is primarily related to increased resting tone of the internal anal sphincter, leading to reduced blood flow to the posterior midline of the anal canal.3,4 This relative ischemia prevents proper healing of the fissure and contributes to its chronicity. In addition, repeated trauma during defecation perpetuates the cycle of pain and spasm, making spontaneous healing unlikely in chronic cases.5 Traditionally, management of chronic anal fissure included conservative measures such as dietary modification, stool softeners, and sitz baths, followed by surgical intervention in refractory cases.6 Lateral internal sphincterotomy has been considered the gold standard surgical treatment; however, it carries risks such as fecal incontinence and other postoperative complications. As a result, there has been a growing interest in non-surgical pharmacological therapies aimed at reducing sphincter hypertonia.7 Topical calcium channel blockers, particularly nifedipine and diltiazem, have emerged as effective alternatives to surgery.8 These agents act by inhibiting calcium influx into smooth muscle cells, resulting in relaxation of the internal anal sphincter. This leads to reduced anal pressure, improved blood flow, and enhanced healing of the fissure. Both drugs are widely used due to their ease of application, minimal systemic side effects, and outpatient-based management approach.9, 10 Despite their established use, comparative evidence regarding the superiority of nifedipine versus diltiazem remains limited and inconsistent. Some studies suggest marginal differences in pain relief and healing rates, while others report comparable outcomes between the two agents. Therefore, direct comparison in a controlled clinical setting is essential to guide optimal therapeutic choice. In the context of increasing preference for non-invasive treatment options, understanding the relative efficacy of these two topical agents is clinically important. Selection of the most effective drug can improve patient compliance, reduce treatment duration, and decrease the need for surgical intervention. The rationale is to identify the more effective first-line topical therapy, thereby optimizing non-surgical management of chronic anal fissure, improving patient compliance, and potentially reducing the need for surgical intervention in routine clinical practice. AIMS AND OBJECTIVES To compare the effectiveness of topical nifedipine and topical diltiazem in the management of chronic anal fissure.

This prospective comparative study was conducted at Department of General Surgery, Sree Mookambika Institute of Medical Sciences over a period of 15 months from February 2025 to April 2026. A total of 60 patients diagnosed with chronic anal fissure attending the surgical outpatient department were enrolled after obtaining informed written consent. Patients were randomly assigned into two equal groups of 30 each. Group A received topical nifedipine ointment and Group B received topical diltiazem ointment, both applied as per standard dosage regimen twice daily. Inclusion criteria included patients aged above 18 years of either gender diagnosed with chronic anal fissure lasting more than 6 weeks, presence of classical symptoms such as pain during defecation and bleeding per rectum, and willingness to participate in the study with regular follow-up. Patients who had not received prior topical calcium channel blockers or surgical intervention for anal fissure were included. Exclusion criteria included patients with acute anal fissure, secondary fissures due to inflammatory bowel disease, tuberculosis, malignancy, or sexually transmitted infections, pregnant and lactating women, patients with previous anorectal surgery, and those unwilling or unable to comply with follow-up visits. All patients diagnosed with chronic anal fissure who met the inclusion criteria were enrolled in the study after obtaining informed written consent. A detailed clinical history was taken, including duration of symptoms, severity of pain during defecation, bleeding per rectum, constipation pattern, and previous treatments. A thorough general and per rectal examination was performed in all patients under appropriate privacy and analgesia. Diagnosis of chronic anal fissure was confirmed based on clinical findings such as a posterior midline fissure with indurated margins, sentinel pile, and exposed internal sphincter fibers in some cases. After enrolment, patients were randomly allocated into two equal groups of 30 each. Group A received topical nifedipine ointment (0.2%) and Group B received topical diltiazem ointment (2%). Patients were instructed regarding correct application technique, where a small amount of ointment was applied gently to the anal verge and just inside the anal canal using a gloved finger, twice daily for a period of six weeks. All patients were advised to maintain a high-fibre diet, adequate hydration, stool softeners when required, and avoidance of straining during defecation to ensure optimal healing conditions. Patients were reviewed at regular follow-up intervals at 2 weeks, 4 weeks, and 6 weeks. At each visit, pain intensity was assessed using the Visual Analogue Scale (VAS), ranging from 0 (no pain) to 10 (worst pain). Clinical examination was performed to assess fissure healing, reduction in sphincter spasm, and presence or absence of bleeding. Healing was defined as complete epithelialization of the fissure with absence of symptoms. Treatment compliance was assessed based on patient-reported adherence to medication regimen. Any adverse effects such as headache, flushing, local irritation, dizziness, or hypotension were documented at each visit. Patients who failed to comply with treatment or follow-up were excluded from final analysis. The primary outcome measures were reduction in pain score and complete fissure healing rate at the end of 6 weeks. Secondary outcomes included reduction in bleeding episodes, improvement in sphincter spasm, and occurrence of side effects. All clinical findings were recorded in a structured proforma and analysed for comparison between the two treatment groups.

Both groups were comparable at baseline with no statistically significant differences. This ensures uniformity for assessing treatment outcomes. Table 1: Baseline Characteristics of Study Population Variable Nifedipine (n=30) Diltiazem (n=30) p-value Age (years, mean ± SD) 38.6 ± 10.4 39.2 ± 9.8 0.81 Male (%) 60% 56.7% 0.79 Female (%) 40% 43.3% 0.79 Baseline VAS pain score 8.1 ± 1.0 8.0 ± 1.1 0.72 Both groups showed significant reduction in pain scores over time. However, nifedipine demonstrated faster and greater pain relief compared to diltiazem, particularly from the second week onwards. Table 2: Pain Score Reduction (VAS) Follow-up Nifedipine Diltiazem p-value Baseline 8.1 ± 1.0 8.0 ± 1.1 0.72 2 weeks 4.2 ± 1.1 5.1 ± 1.2 0.01 4 weeks 2.3 ± 0.9 3.1 ± 1.0 0.02 6 weeks 0.8 ± 0.6 1.4 ± 0.7 0.03 Complete fissure healing was higher in the nifedipine group at 6 weeks. Although early healing rates were comparable, nifedipine showed superior overall healing by the end of the study period. Table 3: Fissure Healing Rate Time point Nifedipine n (%) Diltiazem n (%) p-value 4 weeks 18 (60%) 14 (46.7%) 0.28 6 weeks 27 (90%) 22 (73.3%) 0.04 Both groups showed marked reduction in bleeding symptoms over time. Nifedipine showed a higher percentage of complete symptom resolution, though not statistically significant. Table 4: Reduction in Bleeding Per Rectum Time point Nifedipine n (%) Diltiazem n (%) p-value 2 weeks 16 (53.3%) 12 (40%) 0.29 6 weeks 28 (93.3%) 24 (80%) 0.14 Reduction in sphincter spasm was better in the nifedipine group, although the difference did not reach statistical significance. Both drugs effectively reduced anal sphincter tone. Table 5: Sphincter Spasm Reduction Outcome at 6 weeks Nifedipine n (%) Diltiazem n (%) p-value Significant reduction 26 (86.7%) 21 (70%) 0.12 Both drugs were well tolerated with minimal adverse effects. No statistically significant difference was observed in the safety profile between the two groups. Table 6: Adverse Effects Side Effect Nifedipine n (%) Diltiazem n (%) p-value Headache 3 (10%) 2 (6.7%) 0.64 Local irritation 2 (6.7%) 3 (10%) 0.64 Hypotension 1 (3.3%) 1 (3.3%) 1.00 Nifedipine showed a higher overall treatment success rate compared to diltiazem. A lower treatment failure rate was also observed in the nifedipine group. Table 7: Outcome Outcome Nifedipine n (%) Diltiazem n (%) p-value Complete symptom relief 26 (86.7%) 20 (66.7%) 0.04 Treatment failure 4 (13.3%) 10 (33.3%) 0.04

Chronic anal fissure is a common anorectal disorder associated with severe pain, bleeding per rectum, and sphincter spasm, often leading to significant impairment in quality of life. In the present study, 60 patients were equally allocated to receive topical nifedipine or topical diltiazem. Baseline characteristics were comparable between the two groups, allowing an unbiased assessment of treatment outcomes. Both treatment modalities resulted in significant clinical improvement; however, patients treated with nifedipine demonstrated earlier and greater symptom relief. At the end of six weeks, pain reduction was achieved in 26 (86.7%) patients receiving nifedipine compared with 20 (66.7%) patients receiving diltiazem. Significant pain relief by the second week was observed in 18 (60%) patients in the nifedipine group compared to 12 (40%) patients in the diltiazem group. Similar findings were reported by Sanat ZM et al.10 who demonstrated significantly earlier pain relief with nifedipine compared with diltiazem (P<0.001). Likewise, Kujur AD et al.11 observed substantial improvement in pain scores with both nifedipine and diltiazem therapy. Fissure healing was observed in both treatment groups, although the healing rate was higher among patients receiving nifedipine. Complete healing at six weeks was achieved in 27 (90%) patients in the nifedipine group compared with 22 (73.3%) patients in the diltiazem group. These findings are comparable with those of Jabbar L et al.12 who reported significantly superior healing rates with topical nifedipine compared with diltiazem. Similarly, Sanat ZM et al.10 reported remission rates of 77.4% with nifedipine and 54% with diltiazem after eight weeks of treatment. In contrast, Kumar A et al.13 found comparable healing rates between nifedipine (70.9%) and diltiazem (67.3%), suggesting that both calcium channel blockers are effective non-surgical treatment options. Improvement in bleeding per rectum and reduction in sphincter spasm were also more pronounced in the nifedipine group. Resolution of bleeding was observed in 28 (93.3%) patients receiving nifedipine compared with 24 (80%) patients receiving diltiazem. Similarly, sphincter spasm reduction occurred in 26 (86.7%) and 21 (70%) patients, respectively. These findings support the mechanism of chemical sphincterotomy produced by calcium channel blockers. Vardhani GS et al.14 also demonstrated significant reduction in bleeding and pain scores following topical calcium channel blocker therapy. Likewise, Chanadrashekaraiah KC et al.15 emphasized the effectiveness of nifedipine in reducing sphincter hypertonicity and promoting fissure healing. Both medications were well tolerated with minimal adverse effects. Minor side effects were reported in 6 (20%) patients in each treatment group. Headache, local irritation, and occasional hypotension were the most common complaints, all of which were self-limiting. Similar observations were reported by Kumar A et al.13 who documented excellent tolerability with both agents. Jabbar L et al.12 also found no significant difference in tolerability between nifedipine and diltiazem, with perianal itching and burning sensation being the most frequent adverse events. Treatment success, defined by complete symptom relief and fissure healing, was achieved in 26 (86.7%) patients treated with nifedipine compared with 20 (66.7%) patients receiving diltiazem. These findings are supported by Wang C et al.16 whose meta-analysis of 22 randomized controlled trials involving 1770 participants identified nifedipine as the treatment with the highest healing rate among non-surgical therapies. Similarly, Li P et al.17 reported that nifedipine ranked highest for fissure healing, although diltiazem demonstrated favorable long-term recurrence outcomes. Şahin AG et al.18 further highlighted that while surgical treatment may provide higher healing rates, medical therapies such as diltiazem offer effective symptom control with fewer complications.

Topical nifedipine and diltiazem are both effective and safe medical therapies for the management of chronic anal fissure. Both agents significantly reduce pain, promote fissure healing, decrease sphincter spasm, and improve bleeding symptoms with minimal adverse effects. However, nifedipine demonstrates comparatively better outcomes in terms of faster pain relief, higher healing rates, and greater overall treatment success. Diltiazem remains a suitable alternative with a favourable safety profile and good clinical efficacy. Both drugs can be considered reliable first-line non-surgical treatment options, helping to reduce the need for surgical intervention in appropriately selected patients with chronic anal fissure. FINANCIAL SUPPORT AND SPONSORSHIP Nil. CONFLICTS OF INTEREST There are no conflicts of interest.

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