Most of the time this system stays remarkably free of trouble. With age, however, your body may begin to work less efficiently in some ways and your lifestyle may change. Afterward, digestion may be a problem every now and then. During the chemical process of digestion, food is broken down into pieces tiny enough to be taken into the blood. The blood, in turn, carries these food elements to cells in all parts of the body where they are changed into energy or used to form new structures such as body tissue.
Many people have few, if any, digestive problems related to aging.
Sometimes there are changes affecting the length of time food travels through the system. For example, digestive muscles might move slower or produce less acid. The Digestive System Digestion begins in the mouth. Stomach muscles crush and mix the food with enzymes and acids, creating a mixture called chyme. The stomach allows small amounts of the chyme to enter the duodenum, the first part of the small intestine.