This usually happens to small children and infants. It is an intestinal parasite that lays eggs around the anus.When infected, loss of appetite, insomnia and irritability.
This is also called the vampire fish. This little thing likes to go up the urethra of your penis and just chills out there for a while. They actually wait until a human urinates in the water before it jumps up the penis and swims its way into the body. It uses its poisonous barbs to hold itself in place while it feeds on the fleshy membranes of your stomach.