Final answer:
The large intestine is crucial for water reabsorption and waste elimination from the body. It finishes the digestion process by forming feces from the chyme residue and stores them until defecation. The transit time through the large intestine generally ranges from 12 to 24 hours.
Step-by-step explanation:
The large intestine plays a vital role in the body's digestive process, particularly in the absorption of water and the elimination of wastes. The process begins in the cecum, where liquid waste enters from the small intestine. As the waste moves through the colon, it becomes increasingly solid as a result of water reabsorption. This process is essential for the formation of feces, which consist of undigested food residues, unabsorbed digested substances, bacteria, old epithelial cells, inorganic salts, and a small amount of water to facilitate smooth passage from the body.
The large intestine, which includes the cecum, colon, and rectum, further breaks down food residues, absorbs residual water, electrolytes, and vitamins produced by enteric bacteria. Then, it propels the semisolid feces toward the rectum and finally eliminates them through the anus. The transit time through the large intestine is typically 12 to 24 hours. The rectum stores the feces until they are compacted enough to initiate a defecation reflex, while the anus, regulated by both involuntary and voluntary sphincters, serves as the exit point for fecal matter.