A catheter for diagnosis of sphincter motility by measuring pressure exerted by the sphincter and, when necessary, ablating the sphincter immediately after diagnosis of a dysfunction. The catheter is in the form of an elongate sheath that has a proximal end, a distal end, and a longitudinal portion therebetween, with a manometry data collecting portion and a sphincterotome portion located at the distal end, and a handle assembly located at the proximal end. Embodiments are shown wherein the distal end can be aimed in a direction that facilitates cannulating the sphincter by moving the handle assembly. The catheter is used by maneuvering the distal end of the catheter into a sphincter. The manometry data collecting portion is first aligned with the sphincter and pressure measurements are taken. If it is determined that the sphincter is dysfunctional, the sphincterotome portion is aligned with and used to ablate the dysfunctional sphincter.