a question about urine

[JRB]

I have heard countless times that urine is virtually sterile when it leaves the body. So it this statement is true, I believe the term sterile to mean, pure, devoid of contaminants. So why does bacteria and ammonia form? Is it because it mixes with air?

[adhb]

When used with respect to urine, sterile means not containing any bacteria. Urine is supposed to be sterile, but many people have a very low grade infection that causes no symptoms and really isn't a problem, but there are some bacteria in the urine. However, the main source of bacteria that make a wet diaper smell bad after a little while is bacteria on the skin on the outside of the body. Washing your diaper area thoroughly on a daily basis and cleaning yourself off with baby wipes at every diaper change will greatly reduce the odour problem. Trimming pubic hair also makes it somewhat easier to clean the diaper area with baby wipes.