 [ Symptoms ] i have a tiny blood lump at the end of my spine where the butt crack is soft red pulsing smells like poo what is it  initially i thought it could be a pilonidal cyst but i highly doubt it the smell it produces is enough to scare away people it is like having poop in my pants 247 or 3 hours after a shower noticed it 2 weeks ago the smell was there for 2 months just before the smell the only irregular thing i did was running a little at the gym 4 times 15 minutes in 10 days i am 22 years old averagely fit healthy it is a small lump like an above average zit bloody warm pulsing sweating poop smell [ Disease ] so how long are you going to tolerate this before you see a medical provider have a proper examination and get this treated this still may be a pilonidal cystabscess or even a perirectal abscess a guess of course since i can not examine you either way you need to have this treated and most likely will need a minor surgical procedure