It's a test by Gastro Docs that somehow can register the amount of bacteria, if any, that is in your digestive system. Mine is a week from today. The day before, the list of what I can eat is water and maybe 4-5 things. LOL Knowing the amount will help how I'm treated. In all honesty, I am hoping it IS bacteria they find. At least I will KNOW. And it is very treatable with the right meds.