why my child's urine and poop smells bad   

The smell in urine or stool is not a parameter to identify any disease. Hence it should not be used as a reliable symptom for anything. There can be a smell in the urine if the urine is too concentrated and the child’s water intake is very low. Similarly for stool, each individual has a different flora in resulting in a different smell too. This natural flora can’t be changed once the baby is one or two years old. This smell also depends upon the various processes that take place in the stomach. Due to the body’s flora, some children also have a problem with bad breath. For kids who are more than 2 years of age, the parents can try changing their diet to a more healthy version and some liver purification syrups also can help treat the issue of bad breath.