Efficacy and Safety of Murivenna Anal Infiltration Compared to Diltiazem Topical Application in Chronic Anal Fissure: Protocol for a Prospective, Randomized, Open-Label Clinical Trial - Pratap Shankar KM; Indu Puthan Purayil; Palengara Binitha; Amit Kumar Rai; Sophia Jameela; Azeem Ahmad; Chandra Sekhara Rao Bhogavalli; Narayanam Srikanth; Rabinarayan Acharya (JMIR Research Protocols)