Question

What is undigested food called?

Answer 1

Food is any substance that is consumed in order to provide nutritional support to an organism. Food is typically derived from plants, animals, or fungi and contains essential nutrients such as carbohydrates, fats, proteins, vitamins, and minerals.

Complete answer:
Animals that consume bulk food unavoidably consume some matter that they are unable to use. When unicellular organisms form food vacuoles, the vacuoles eventually fuse with the cell membrane and rupture, releasing indigestible wastes to the outside world. In the colon, or large intestine, substances that cannot be digested, such as cellulose, pass. Water and ions like sodium and chloride are reabsorbed there, and the remaining solid material is retained until it is expelled through the anus.
Cast-off effete (damaged or worn-out) cells from the living mucous membrane and, in higher animals, bacteria that exist in the intestine in a symbiotic relationship are also faecal constituents in species with an alimentary canal. A cell from the mucosal epithelium has a lifespan of four to eight days in higher animals, and specialised cells, such as acid-secretion parietal cells in the stomach, have a life span of one to three years.
Egestion refers to the removal of undigested food from the body via the anus. In humans, egestion is the final step in the digestion process. The undigested food from the small intestine remains in the rectum and exits the body via the anus.
The role of digestion in reducing large complicated molecules into smaller simpler molecules that can pass across membranes, allowing food absorption into cells When substances must be transferred from cell to cell inside a multicellular organism, the same processes take place.

Note:
Thus, green plants, which do not have to digest incoming nutrients, digest stored material, such as starch, before it can be transferred from storage organs to areas of usage, such as expanding buds.