Unless you have been placed on a special diet by your doctor or other medical person, there is no reason to arbitrarily exclude any foods from your diet. If a particular food is shown by experience to consistently cause problems, then exclude that. Introduce new foods slowly, to gauge their affect. The key is to chew your foods thoroughly. It has been described as chew your liquids, drink your solids .
Digestion starts in the mouth.
There are no teeth past the mouth to further break down the foods, nor to mix it with the saliva found in the mouth. Saliva is an integral part of the digestion process. Chew your liquids to mix them with saliva. When they reach the stomach they are mixed with other needed digestive juices, before being passed to the intestine for absorption. Some foods may cause gas.