The presence of bacteria in the urine, such as with a urinary tract infection (UTI), can affect the appearance and smell of urine. When there is an infection in the urinary tract, the urine may take on a foul-smelling odor as well as appear cloudy or bloody.A burning sensation during urination may be a symptom of a UTI.The urine may also have an abnormally sweet odor in uncontrolled diabetes, and some rare genetic conditions can also cause the urine to have an abnormal or strange odor. burning sensation during urination may be a symptom of a UTI. The urine may also have an abnormally sweet odor in uncontrolled diabetes, and some rare genetic conditions can also cause the urine to have an abnormal or strange odor.