Uh, anybody ever hear of bleeding hemoroids? Often men get them, especially when they are overweight. Usually it is bright red blood and off you find it on the underwear, not necessarily just bowel movements.
I'm just saying, don't panic. See if it continues - it may just be a small bleeding spot where some ugly parasite was sucking off the insides of your colon. Or maybe it's not blood, but the leftover deflated red body of a fluke stuck in your bowel movement - I've had those. If it goes on for more than a week, then I'd make an appointment with a doctor.