What are the functions of the digestive system of fish?

The digestive system of fish consists of the mouth and mouth, pharynx, esophagus, stomach, intestines. The intestine is divided into the small intestine, the large intestine, and the rectum, which ends in the anus. Some fish have a cloaca in front of the anus.
The digestive system is not only responsible for the digestion processes in fish. It is also associated with breathing. Inhaling water enters the mouth with small food. And on exhalation, the water is retained by the gill stamens, after which they are sent to the esophagus.