Final answer:
Most salt and water absorption occurs in the small intestine, which absorbs about 90% of the water. The large intestine absorbs the remaining water, contributing to feces formation.
Step-by-step explanation:
The majority of water absorption takes place in the small intestine. Each day, approximately nine liters of fluid enter the small intestine, a mixture of ingested food and beverages and gastrointestinal secretions.
About 90 percent of this water is absorbed in the small intestine due to the concentration gradient between the chyme and epithelial cells, making it the primary site for water reabsorption.
The large intestine absorbs most of the remaining water, helping to convert the liquid chyme residue into semisolid feces. This crucial absorption process is vital for the body's hydration and electrolyte balance.