Hi, Welcome to Healthcaremagic.com. I had gone through your question I can understand your concern about your digestive problem. As per your history you seems to have diagnosed your self as lactose intolerance, but in reality it can be simple food poisoning. Sometime in food poisoning you eat something and after some time you had bowl movements. Some important signs of lactose intolerance are as, bloated feeling, much gas, diarrhea and abdominal cramps. Yes there are many tests like lactose breath test, stool acidity test, more fats in stools, or other tests, which may be used to detect the lactose intolerance. In case you have the deficulties for more than two to three days you need to visit an Gastroenterologist for further evaluation. Hope my answer will help you and visit us back if you have any questions further. Regards Dr Muzaffer Hussain Parray.