A 68-year-old white man is concerned because he thinks he is urinating blood. He noticed it about one month ago, and he thought it was related to sex as he noticed it right after intercourse. However, he has had two other episodes within the past two weeks not related to sexual intercourse. He denies fever, dysuria, frequency, abdominal, back, or pelvic pain. He states he used to have a weak stream and need to urinate at night, but these symptoms have improved since starting finasteride (5α-reductase inhibitor). His past medical history includes BPH, and current medication is finasteride. He has no known drug allergies. Social history includes being an active smoker, smoking 1 pack of cigarettes daily for the past 40 years, and consumes two to three beers on the weekends. Physical examination as follows: body mass index 32; vital signs and examination are within normal limits. An urinalysis with microscopic evaluation is positive for blood with 40 RBCs/HPF; no casts or dysmorphic cells noted