title: Is botulinum toxin injection a better treatment than nitroglycerin ointment for patients with chronic anal fissure?
authors: Department of Colorectal Surgery, John Radcliffe Hospital, Oxford, UK. rowan.collinson@orh.nhs.uk
authors: Rowan J
authors: RJ
authors: Collinson
authors: Neil J Mc C
authors: NJ
authors: Mortensen