Comparative Evaluation of MEBO Ointment and Topical Diltiazem Ointment in the Treatment of Acute Anal Fissure

Inclusion Criteria: * Subjects must be 18 years and above. * Subjects with 3 months (90 days) or less history of painful anal fissure (AF), prior to screening, where AF-related pain-associated with, or following, defecation is experienced at least twice a week during the symptomatic phase, with pain scores at an average of ≥ 3 on an 11-point NRS (Numerical Rating Scale, range 0-10 where 0 = no pain and 10 = worst pain imaginable). * Subjects with an average of ≥4 on an 11-point NRS during the screening phase for worst anal pain associated with, or following, defecation for the most recent 3 days on which the subject has defecated. * Subjects with evidence of a radial fissure, with induration at the edges, seen on anal examination. * Willing to stop all other concomitant topical preparations applied perianally prior to commencing study treatment, and throughout the study. There will be a "washout" period of at least 2 weeks prior to commencing the study for subjects who were using other concomitant topical preparations applied perianally. * Able to give consent Exclusion Criteria: * Subjects unwilling to be examined for AF. * Subjects who have undergone the following procedures: * Lateral sphincterotomy or anal stretch or other previous surgery involving the anal canal or perianal region (hemorrhoidectomy, anal fistula surgery). * Incision of perianal abcess. * Subjects who have had sub-fissure injection of botulinum toxin within 6 months period prior to scr…