Asparagus pee What causes the smell Medical News TodaySpear Grass may cause a noticeable scent within your urine. It is generally acknowledged that eating this green vegetable can lead to a strong aroma during a trip to the restroom. If you see an offensive aroma after enjoying a meal containing asparagus, do not be alarmed. It is just a normal reaction that occurs within the body. Be reassured that the odor is not dangerous and will go away eventually.