I would like to find out why you can get diarrhea with cardiac problems like braycardia?

No direct cause: Could be drug induce or a decreased blood flow to the intestine creating transient ischemic bowel if you have heart failure. Bradycardia only without any other symptoms or complication it's a rare cause of diarrhea and association can be coincidental. Consult your doctor for a better assessment by a good history and physical exam.