There are many reasons why blood appears in the underwear of male patients. If the patient is a male patient over 40 years old with dry and thin stools and increased bowel movements, consider the occurrence of rectal tumors and blood on the underwear related to the tumor. Men with brown discharge on their underwear should pay attention to whether the discharge is from the glans or from the urethra. The vast majority of them may be urethral discharge, and they must bring urethral discharge for examination to see if there is gonococcus, mycoplasma or chlamydia, and the examination of the discharge can determine what the disease is. There may also be bleeding, and brown discharge will occur when bleeding occurs. The cause of bleeding may be inflammation of the glans of the foreskin, or damage to the mucous membrane of the urethra, or hematuria caused by urinary stones. If there is no other abnormal performance, you should wash in time, wash your underwear frequently every day and pay attention to personal hygiene.