text: what does it mean when your underwear has a bad scent, like cat pee? don't mean to gross anyone out, but its been happening to me and i don't know what it means! i notice it when i go to the bathroom! it reeks of a scent similar to cat pee. you may have a bladder infection or it could be due to some medications you are taking.  some medications, especially antibiotics, tend to discolor your urine and give it a noticeble odor.