have you had a scope done to be checked for colitis?? there are a couple different types of colitis. One type is from antibiotics. Have you been on any antibiotics in the past couple months?? Also, there is ulcerative colitis. This is a type of inflammatroy bowel disease, and one of its symptoms are bloody diarreah and stool. You may also be losing weight and feel sick to your stomach, although your only (and the most common symptom) may be bloody stool. don't worry about it too much! what ever it is it can be treated!!
go now do not delay only a specialest can tell you how serious it is but it is nothing you want to put off period. have your regular doctor to recomend a gastro / digestive specialest and make sure they come highly recomended blood in the stool is very serious but it couold be linked to something minor do not try to self diagnose.god blees