My Anus Is Often Moist. At First It Was Just

my anus is often moist. At first it was just when I woke in the morning, it would feel a bit moist, but now I'm noticing it during the day. It is not sweat running down my back.
I go to the toilet to wipe in order to dry, and it appears light brown, like a babies........
There isn't much, but enough to leave a mark on my undies.