Final answer:
Food that reaches the large intestine is transformed from liquid chyme residue into semisolid feces through water absorption. Composed of various undigested and unabsorbed substances and aided by intestinal bacteria, the final waste is stored in the rectum until defecation.
Step-by-step explanation:
When food reaches the large intestine, it has already had most of its nutrients absorbed in the small intestine. The large intestine's main role is the absorption of the remaining water from the liquid chyme residue, a process that converts this residue into semisolid feces or stool. The colon, which is the main part of the large intestine, assimilates any leftover salts and water. Additionally, the large intestine hosts a diverse microbiota that aids in further digestion. The semi-solid waste is then moved through the colon by peristaltic movements and stored in the rectum until eliminated through the anus.