The digestive system is a complex system involving many organs.
It starts with the mouth, in which the food is mechanically ground using the teeth and mixed with Enzymatic and antiseptic fluid (saliva).
It passes through a tube (esophagus) into the stomach. The stomach is a big tank in which the food is immersed with strong acid. The acid kills germs that may exist in the food and breaks down the food into its components. Valves prevent the food from exiting the stomach prematurely. If the upper valve is not working properly we feel Heartburn. Muscles in the stomach stir the food so it is exposed evenly to the acid.
After the acid operation is done, the food is returned to the normal pH level by mixing it with baking soda and driven downstream by muscle operation.
The food enters the “small intestines” where most of the nutrients from the food are absorbed into the bloodstream by special filtering cells. Muscles in the intestines push the food down the intestines. If there is a big bacteria population in the small intestines, they eat the food and expel gases that can prevent the normal small intestines operation.
From the small intestines, the remaining food is transferred to the large intestines.
In the large intestines, the bacteria population exists and does its operation. They produce some vitamins like K and B12 and communicate with our brain. In the colon, water is absorbed into the body.
The solid remains are stored in its lower part until we go to the toilet and emit it.
In such a large and complex system, many things can go wrong.
On this site, we are dealing with some things that can go wrong.