hello, i am a little concerened as i have a condition that when i drink cola my urine seems to change colour, as the same colour as the colour of the cola but does not stay like that, i drink a lot of cola and quite often as i work hard and get quite thirsty, i have passed a kidney stone before and i have a bulging disc in my lower left back that causes me pain when it swells(daily minimal discomfort), although now i am thinking it could all be related, could you give me your opinion, thank you kindly. changes in urine colour are now and then every few days or sometimes weeks