The process of digestion
Even though IBS is quite common, how and why it affects people is still something of a mystery. One reason is the vast role and complex functioning of the digestive system. It does more than just digest food and absorb nutrients. To better understand IBS, we’ll look more closely at how the digestive system works.
The digestive process begins in the mouth when food is chewed into more easily digestible pieces. Saliva starts the process of breaking down starches into smaller molecules and makes food wetter, softer, and easier to swallow.
As swallowed food enters the esophagus, it’s pushed onward by the coordinated contractions of muscles in the walls of the entire digestive tract. When food reaches the stomach, it is stored, mixed with stomach acid and digestive enzymes, and slowly emptied into the small intestine. Enzymes released in the stomach begin the digestion of proteins.
Digestion then continues in the small intestine, where the digestive juices, enzymes, and bile produced by the pancreas, liver, and gallbladder work together to break down carbohydrates, fats, and proteins into simple sugars, fatty acids, and amino acids. These nutrients are then absorbed through the walls of the small intestine into blood vessels and transported throughout the body.
Any food molecules that aren’t absorbed are emptied into the colon and eventually get eliminated from the body. The colon absorbs excess water, and bacteria in the colon break down the remaining material, transforming it into solid stool. Then the colon’s muscular walls contract to push out the stool during a bowel movement.