Cystometrogram CMG

A diagnostic test to measure the nerve and muscle function of the bladder. A small catheter is placed in the bladder, and the residual urine measured. The bladder is then filled with either carbon dioxide gas or water and the volumes and pressures are measured as the bladder fills and empties. Frequently the electrical activity of the sphincter muscle, electromyogram/EMG), is measured in a manner similar to an electrocardiogram. Some physicians also measure the abdominal pressure by placing a small catheter in the rectum as well.