I did a colonoscopy. and only thing they found was internal hemorrhoids 3 weeks ago. last few days my stomach been burning and cramping pains on and off all day they get pretty bad at time and and im passing bright red blood ? what could it be?

In view of your otherwise normal colonoscopy,I don't think you have to worry about inflammatory bowel disease like ulcerative colitis. The bleeding is most likely from hemorrhoids. Your current abdominal symptoms could be from a viral gastroenteritis,food poisoning or from intolerance of something you ate. Eat only soft bland foods, Call your gastroenterologist if symptoms persist or Go to the ER