non-HRM, to generate a more refined view. An additional benefit to HR-ARM and HD-ARM is the increased ease in analyzing the results as pressure readings are displayed in both color and as a line plot. Accompanying the benefits shared by both high-resolution and high-definition methods, the HD-ARM method employs additional sensors placed circumferentially around the catheter allowing for closer interpretation of individual sensor pressure readings. In comparison to non-HRM, however, both of the newer methods utilize equipment that is more expensive and has a shorter design life. Procedure Equipment The specifics of the equipment used for the procedure will ultimately depend on the type of manometry and the manufacturer of the device. Nonetheless, most share some common features. Catheter - used to insert the probe and balloon into the anorectum. The catheter may be water-perfused, solid-state or air-charged. Probe - contains sensors whose number and arrangement depend on the manufacturer and type of manometry Sensors - records pressures and transmits them back to the controller software Balloon - used to assess sensation when inflated with air. Most balloons used are non-latex and are manufactured to expand to 400 ml. A separate catheter with a water-inflatable balloon may be used to conduct a balloon expulsion test. Software - receives data from sensors. Data is then used to calculate values to be used for analysis and to provide visual feedback. Technique In 2019, the International Anorectal Physiology Working Group (IAPWG) released a standardized testing protocol for the use of anorectal manometry. One of the goals of this protocol was to standardize procedural techniques to better facilitate meaningful data sharing. This protocol is the most recent published guideline for anorectal manometry since the one published in 2002 which was not widely adopted. Preparation Fasting is not a requirement for this procedure. Patients are informed as to how the procedure is performed, its benefits and risks. Risks include the possibility of developing discomfort, pain, minor bleeding, dizziness or a rare perforation. In the testing room, the patient is placed on their left side with their knees bent. A digital rectal exam is then preformed prior to the procedure to evaluate initial anatomy and function, check for stool, and to assess patient's understanding of the verbal instructions employed during the procedure. Tests Anorectal manometry is often performed alongside a rectal sensory test (RST) and a balloon expulsion test (BET) The RST is preformed after the