Q. A 35-year-old female presents to clinic with urinary incontinence. She reports that she has to use the bathroom frequently and often leaks urine when she sneezes, coughs, or exercises. She denies pain with intercourse, and reports normal bowel movements. She has no other significant medical history and is not currently taking any medications. On physical examination, the patient weighs 62 kg (136 lb), is 160 cm (5 ft 2 in) tall, her BMI is 24 kg/m2, temperature is 37 degrees Celsius (98.6 degrees Fahrenheit), pulse 58/min, respirations 12/min, and blood pressure 122/80 mm Hg. Her cardiopulmonary examination is normal. The patient's abdomen is soft and non-tender, and there is no evidence of muscle weakness or atrophy. Inspection of her vulva, labia, and urethral opening reveals no abnormalities or signs of infection. A speculum examination reveals normal appearing vaginal wall rugosities, a normal appearing cervical os with no ulcerations or discharge, and Valsalva maneuver demonstrated no evidence of prolapse. A digital rectal examination is also normal and Hemoccult negative. You order blood work, an abdominal x-ray, and a pelvic ultrasound. Laboratory studies reveal a normal complete blood count, normal kidney function, and normal electrolytes. An abdominal x-ray is also normal. The pelvic ultrasound shows a small bladder and a thinned bladder wall. Based on the information you have at this point, what is the most likely diagnosis?