What Causes Anal Leakage?

I am having an anal leakage problem and I am not sure why. I eat fairly well, I do drink alcohol on the weekends, but I work out a ton because I am a college football player. The symptoms do not occur every day but they happen often 2-3 days in a row and I cannot find the correlation. My butt will usually feel wet and then I will check my boxers and it doesn t really look like anything but butt sweat is in there but it smells foul. This will happen at any time of the day. I have tried taking a probiotic, which I thought helped at first but the problem has come back. I am not sure if it is a bacterial imbalance or if I have an anal fissure of some kind but I do not experience any abdominal pain. I also usually have runny stool but not always. I really do not know what could be causing this. Any thoughts?