Hi.... Welcome to healthcare magic. According to your complain you have problem of green stool that may be because of more iron rich food are you taken or iron supplements or other reasons. Food intolerance like gluten foods may lead to this type of symptoms. Protozoa infection like giardia cause green stool problem. Viral gastritis may ruled out. Consult a gastroenterologist for further diagnosis. Do a complete blood cell count and stool examination test to check infection present or not.. Detail history and investigation give exact idea about problems. I hope my guidance helpful to you.. Take care. Thank you.