Hi,
Welcome to the ehealth forum and I am glad to help you out. The normal odor of urine is aromatic. Some foods (such as asparagus), vitamins, and antibiotics (such as penicillin) can cause urine to develop an unusual odour.Just check out if this is the cause of the offensive urine odor.If not then medical conditions that can cause it like Hepatic (liver) failure, Ketonuria, Maple sugar urine disease (very rare), Phenylketonuria (rare), Rectal fistula and urinary tract infection have to be probed.
I feel that a consultation of a urologist and complete urine examination and culture will help in confirmation of a diagnosis. It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care.