Being one of 13 siblings and the 2nd youngest in the family I learnt at an early age to eat fast or miss out on all the good bits of food. I still hear the voice of my mother telling me to slow down and chew my food properly. Even now I still have a bad habit of gulping down my food as quickly as possible. Inadequate chewing of food means the digestive enzymes in the mouth gets little chance to chemically break down substances.
Our digestive tract does not handle crunchy foods too well either. Crunchy foods like chippies, biscuits, toast and fried foods were never part of our normal diet. This is another reason why we chew our food properly and slowly. The digestive enzymes in our stomach have to work a lot harder to process hard substances. Of course when you are young you think you know better and everything will be alright.
Stomach problems are not just from inadequate chewing, overeating or bad food combinations. Prolonged stress and excessive alcohol consumption can damage the lining of the intestines as well. So what is the answer? I guess it depends on what school of thought you favour. The traditional approach would simple be to take a tablet to hold the acid down in the stomach. The intermediary answer would be to just stay away from food intolerances and allergies. The alternative person would probably persevere to search out a natural cure.