Wheat and its relatives are the commonest cause of food induced illness. Lactose, the sugar in milk, is the second biggest cause of problems. As many people leave childhood, the quantity of lactose they can digest is reduced. Any extra is utilised by bacteria in the digestive tract and produces considerable discomfort.
Many people suffer from other foodstuffs.
A processed diet often makes these problems far worse. The food combining diet will help prevent food allergy and intolerance from developing, by ensuring a diet based on a broad range of foods, and a healthy digestive system, but where problems have arisen the food combining diet makes it easier to identify and avoid problem foods because they are not hidden in refined mixtures.
Sending off hair samples for analysis and similar testing methods have no scientific basis. Self diagnosis of food allergy can also be dangerous. If you exclude a food that causes an allergy, your sensitivity to the food can increase dramatically. If you then re-introduce the food, it can cause a dangerous shock reaction. For this reason allergy testing should only be done under properly qualified medical supervision.