pain and possible injury to the small (small intestine) or large intestine caused by expansion of trapped gases (intestinal gas) when a person, especially a pilot or underwater diver, goes from areas of greater pressure to areas of less pressure. Under normal atmospheric conditions, intestinal discomfort can be felt when air or gas collects in the intestines. Relief is obtained by expelling the gas when it begins to expand the intestinal walls. When a pilot ascends to high altitudes, the pressures exerted upon the body are reduced. Gases in the body expand proportionally to the reduction in pressure. Swallowed air or gases formed by the breakdown of food products, if not expelled by belching or through the anus, will distend the intestines. On the other hand, divers (underwater diving), as they descend underwater, experience an increasing amount of pressure, which compresses the gases within their bodies. As they return to the surface, bodily gases begin to expand, and the intestines may distend.

The usual symptoms are a bloated feeling and pain. If the gas cannot be relieved, the intestinal tissue may rupture or the pain may be severe enough to cause fainting. Intestinal squeeze can be avoided in many cases by selecting a diet before the activity that does not usually cause intestinal gas. Carbonated beverages, cabbage, beans, fruits, nuts, and spicy foods should be avoided. See also decompression sickness.