In response to the enquiry: “Does ice water cause gas?”
Many people get severe stomachaches from drinking ice water and eating cold ice cream. We know this well.
These severe stomachaches feel like bloating discomfort and the onset of the stomachaches is sudden.
Drinking hot water, room temperature water, or hot tea or hot coffee does not seem to cause such stomachaches and intense bloating discomfort.
The specific mechanism as to why ice water causes such intense stomachache, bloating, tightness in the stomach and severe acid reflex is not really known nor studied.
My thoughts are that ice water and ice cream trigger a sudden tightening of the stomach muscles because of the cold temperature of the ice water and the ice cream. This sudden contraction of the stomach muscles used a sudden increase of muscular energy. The autonomic stomach nerves may sense that the stomach muscles are fatigued and thus issue a command to produce more stomach acid to help digestion.
In a sense, the autonomic stomach nerves may have sensed that the stomach muscles have been frozen and has become dysfunctional so they issue an autonomic command to produce more stomach acid to compensate for this perceived dysfunction in digestion.