When my close friend got bariatric surgery, the doctors told him the carbonatiob would expand his stomach much faster and so seltzer was forbidden forever. Might also apply to all stomachs.
Reading the thread, the comment you responded to was using "normal person" as a contrast against someone who had undergone bariatric surgery (which stomach stapling is a variety of).
There are videos that show that most of the carbonation effervesces in your esophagus and mouth, and most of the carbonation is gone by the time it reaches your stomach.
