To let loose, with extreme force and vigor, an excessive stream of diarrhea. One does not necessarily have to use a toilet for a fowler to occur; however, any area chosen as a bathroom suffers extreme damage as a result of a fowler.
Example #1: My fowler ruined my Honda.
Example #2: Bravo Burger is the home of the fowler.
Example #3: Dave completely missed the toilet bowl with his fowler.