Cystometry involves measuring pressures in which areas along with patient sensation?

• A. Bladder and urethra
• B. Bladder and rectum
• C. Kidneys and bladder
• D. Bladder and abdomen

Answer: (B)

Cystometry assesses how the bladder stores urine by filling it and tracking pressure changes inside the bladder while also noting the patient’s sensations of filling. To interpret those bladder pressures accurately, a second pressure is recorded from a rectal catheter, which serves as a proxy for intra-abdominal pressure. By comparing bladder pressure to abdominal pressure, you can derive detrusor pressure and see how the bladder muscle behaves during filling. Recording what the patient feels at different volumes—first sensation, urge, and strong urge—complements the pressure data to give a full picture of storage function. So the pressures measured are in the bladder and the rectum (to gauge abdominal pressure), alongside the patient’s sensation during filling. Other sites like kidneys aren’t involved in cystometry, and while abdominal pressure is relevant, the rectum is the standard practical reference used in this test.