My 1.5 Year Old Toddlers Stool Has A Chemical Smell...almost

My 1.5 year old toddlers stool has a chemical smell...almost like ammonia. She seems to go through periods of the stool smelling like this, and than it seems to go away for a while. This started a few months ago and has been cycling back and forth ever since. For the most part, her stoop consistency is normal...its just the smell. Is this something I should be worried about?