A method for operating a computer-controlled washer/disinfector for cleaning a medical endoscope, said method comprising the steps of: storing in memory identification and operating characteristics for a plurality of clean endoscopes, said operating characteristics including flow characteristics for each lumen within an endoscope and a blockage threshold flow coefficient for each lumen within an endoscope; connecting each lumen of an endoscope to be cleaned to a fluid distribution system for selectively conveying pressurized air or pressurized fluids through lumens in an endoscope; identifying the type of endoscope to be cleaned in said washer/disinfector; determining said blockage threshold flow coefficient for each lumen for said endoscope to be cleaned; pressurizing each lumen in said endoscope individually and determining an actual flow coefficient through said lumen; determining whether said endoscope is suitable for cleaning by comparing said actual flow coefficients for a lumen in said endoscope to said blockage threshold flow coefficient for said lumen; and determining whether a connection to a lumen in said endoscope is properly connected based upon said flow coefficient through said lumen; further comprising the step of determining if two lumens merge into a single lumen within said endoscope by: determining an individual air flow coefficient for each of two lumens in said endoscope; determining a combined air flow for said two lumens in said endoscope; and comparing the air flow coefficient for said two lumens to a sum of the individual air flow coefficients of said two lumens. storing in memory identification and operating characteristics for a plurality of clean endoscopes, said operating characteristics including flow characteristics for each lumen within an endoscope and a blockage threshold flow coefficient for each lumen within an endoscope; connecting each lumen of an endoscope to be cleaned to a fluid distribution system for selectively conveying pressurized air or pressurized fluids through lumens in an endoscope; identifying the type of endoscope to be cleaned in said washer/disinfector; determining said blockage threshold flow coefficient for each lumen for said endoscope to be cleaned; pressurizing each lumen in said endoscope individually and determining an actual flow coefficient through said lumen; determining whether said endoscope is suitable for cleaning by comparing said actual flow coefficients for a lumen in said endoscope to said blockage threshold flow coefficient for said lumen; and determining whether a connection to a lumen in said endoscope is properly connected based upon said flow coefficient through said lumen; further comprising the step of determining if two lumens merge into a single lumen within said endoscope by: determining an individual air flow coefficient for each of two lumens in said endoscope; determining a combined air flow for said two lumens in said endoscope; and comparing the air flow coefficient for said two lumens to a sum of the individual air flow coefficients of said two lumens. determining an individual air flow coefficient for each of two lumens in said endoscope; determining a combined air flow for said two lumens in said endoscope; and comparing the air flow coefficient for said two lumens to a sum of the individual air flow coefficients of said two lumens.