It allows the patient who may be going to surgery just enough moisture to keep their esophagus moist (as the esophagus does not provide mucus to itself) without having enough water in quantity to be a danger when anesthetized (of throwing up and getting into the lungs).

Postoperatively, it is the same idea plus the bowels may have a temporary paralysis called “paralytic ileus” that can last for 24 to 48 hours.

Also in chemotherapy, patients complain of Xerostomia (dry mouth) and may also have oral mucosal superficial lesions that are comforted by the cool ice chips.

Also, ice chips can be slowly introduced into your gastrointestinal system because people tend to suck on them or bite them. When you gulp huge sips of water can aspirate (breathe it in) or choke on the water coming back up during anesthesia. So patients are given ice chips prior to surgery. They used to be given to patients in labor, but many doctors today allow small cups of clear liquids to their clients. After surgery, they will offer ice chips until a patient is cleared for water/ and or food

After surgery for a lot people drinking water can cause them to become nauseous. Also after some surgeries fluids into the digestive tract isn’t a good thing and needs to be done very gradually. So ice chips is a good option. Ice has less volume than water and can ease the feeling of thirst. The volume is extremely limited and it takes awhile to get much liquid from them. So ice chips is just a slow start.