Brief Answer:
Considerations

Detailed Answer:
thank you for sending the question.

We definitely want to try to find the source of the blood that you found in your underwear. Considerations include rectal bleeding or possibly bleeding from the urinary tract.

With your prior history of radiation to the prostate this can sometimes increase the risk of proctitis which can cause some gastrointestinal bleeding.

At this time I would recommend that you
make an appointment with your primary care doctor for a full examination with laboratory studies. Once the source of the bleeding is identified you may need further examination with possibly a colonoscopy or possibly urethroscopy.

if you're feeling lightheaded or week I would recommend that you proceed to the emergency room immediately for evaluation. Otherwise I would call your primary care doctor in the morning to obtain an appointment.

Thanks again for sending your question. Please let me know if you have any additional specific concerns.

Sincerely,

Dr. Galamaga

---