I am a 36-year-old male. Today morning when I went to the washroom, I noticed a dried blood stain on my underwear making a patch on the backside of my underwear near the anus area. I didn't have any pain nor I could find out where it came from. I have noticed these symptoms twice in a couple of weeks. I am not having any kind of pain in my anus. Please doctor could can you suggest me anything about what's going on with my body? recently for a couple of months, I started drinking black coffee in the morning with lemon on empty stomach. Is this the reason for it? I am tense now about whether I am encountered any serious disease. I am a student pursuing my Ph.D. in the United States.