Gas pain
Gas pain was abdominal discomfort caused by the accumulation of gas in one's digestive system. They could be relieved by farting. (LD: "Grounded")
In 2377, while trying to determine where The Doctor was being detained, Neelix served Gar a meal whose base was Talaxian wormroot. Upon hearing this, Tuvok asked if Neelix had poisoned Gar. Neelix assured the Vulcan that Gar was only having gas pains. (VOY: "Critical Care")