Hello and welcome to Healthcare Magic. Thanks for your query.
There could be two possibilities for the passage of blood and some other clot-like substance in your urine:
1) a stone in the ureter
2) a urinary tract infection
(and the clot like fatty material could be a "cast")
This problem definitely needs to be looked into and I would advise you to have a urine routine test done to determine the possible cause of your symptoms. In addition, I would suggest that you drink plenty of fluids. Drinking Cranberry juice can also help since it is a natural urinary antiseptic.
Wish you all the best.
Dr. Jonas Sundarakumar