Can groin hernias cause bowel and bladder problems?

Yes. An inguinal hernia is a hole in the muscle layers of the abdominal wall which allows a sac of the abdominal lining to come through it. That sac is open at the base and will, sometimes, allow bowel or fatty tissue or bladder to enter the sac and become irritated, stuck or in worst case injured and gangrenous. Symptoms can vary based on what is in the sac and how badly trapped and irritated it is.
Yes. If hernia is stuck then can cause problems depending what is stuck in them.