Hi and welcome to Healthcaremagic. I understand your concerns. Well I think that this is not serious since there may be urethral injury or bladder injury during catheter application. However, if bleeding persist, you should have catheter reinserted and cystoscopy should be done since some other issues such as polyps or tumor recurrence may be underlying cause. So urologist consult is required. Till that drink plenty of fluids to promote urination. I hope I have answered you query Kindly regards. Wish you a good health.