Your body takes in the food that you are eating and then it has to break it down. Your stomach is an amazing machine that is able to break down the items that you eat and turn them into useful pieces of fuel. Your body needs a lot of vitamins, minerals and proteins to keep it in top condition and it gets those items from the food that you eat.
After you eat something, your stomach breaks it down into the smaller elements that it needs. That is, assuming you have had a normal meal. If you have suddenly overwhelmed your stomach with piles of food that it’s not used to, it can be overrun with items it is supposed to be breaking down. As it is only one stomach, it will be unable to keep up with the workload. That means some of those items are going to pass through without being broken down into smaller pieces. As they continue through your digestive tract they are going to start to clog things up. They could get stuck to the walls, pile up in your colon and soon you will find that you are suffering from constipation.