I received methadone several years ago for burn injuries, I can't recall ever feeling sick to my stomach.

Well.. Depends bcuz some foods can harm your stomach that you are allergic too.. also physical injuries.. for example someone punches you in the stomach and causes internal bleeding.. also many sicknesses and viruses and harm the stomach..

One of the most common injuries to the abdomen is a blow to the solar plexus, which gives a momentary paralysis of the diaphragm and the sensation of having “the wind knocked out of you.” These injuries can happen from being hit in the stomach with a shoulder, a helmet, or falling onto a hard object such as a ball.

Frederic Bowreman Jessett has written:

'The surgical diseases and injuries of the stomach and intestines'

Neurological conditions or injuries, injuries to the mouth or throat, obstructions of the stomach, cancer or ulcerative conditions of the gastrointestinal tract, and certain surgical procedures