Encyclopaedia Britannica explains that most of the water that a person drinks is absorbed in the intestines; however, many sources disagree about which part of the intestines is most responsible for water absorption. Two different parts of the small intestine are important for absorbing water although the large intestine also removes any water that remains once the digested food reaches the end of the digestive tract.
According to the International Foundation for Functional Gastrointestinal Disorders, the ileum is responsible for absorbing water, bile salts and vitamin B12. The ileum is the last section of the small intestine that precedes the large intestine; however, the foundation explains that water absorption occurs in the upper small intestine as well.
The Encyclopaedia Britannica states that different portions of the digestive system have pores of different sizes. This creates differing rates of water absorption among the various portions of the intestines.
The human body works by converting food to a liquid state to facilitate digestion. The liquefaction process begins in the mouth and continues in the stomach. The National Digestive Diseases Information Clearinghouse explains that when digested food reaches the large intestine at the end of the digestive tract, it's in a liquid state. One of the primary purposes of the digestive tract is to remove this water and convert the feces to a solid form.