Asparagus pee What causes the smell Medical News TodaySpear Grass might cause a noticeable smell in your pee-pee. It is generally acknowledged that consuming this green vegetable can cause a powerful whiff while visiting the restroom. If you see an offensive smell once you've indulged containing asparagus, do not be alarmed. It is just a normal result that occurs within the body. Feel confident that the smell is not dangerous and will fade gradually.