Uterine distension fluid management system and method

A method for operating a fluid management system includes automatically detecting an unstable condition in the system, which may include detecting a large change in the supply fluid amount (indicative of a bag change), detecting a large change in the waste fluid amount (indicative of a bag change), or detecting a large difference between the amount of fluid dispensed as measured by the weight data and the amount of fluid dispensed as measured by the flow data (indicative of a blockage in the supply tubing). The method further includes adjusting the operating mode of the system during the unstable condition, which may include switching to using flow data rather than weight data to track the fluid deficit during a supply bag exchange, halting operation of an outflow pump during a waste container exchange, and/or halting operation of the system during a blockage in the supply tubing.