Nick Swardson tried to gut through some abdominal pain, but he couldn't stomach it ... and it turns out the intestinal distress ain't just gas ... but something much worse.

The comic actor shared a clip from a hospital bed Wednesday morning ... telling his fans not to write off sharp stomach pains as a "super fart" or food poisoning as he did ... because it could be an issue with the appendix.

Nick says he needs emergency surgery to remove his appendix ... and says he's very lucky his appendix didn't burst.

Nick says he was working on a movie before being taken to the hospital ... and he can't wait to update fans on the project ... but that'll have to wait until his medical issues are resolved.

The video ends with Nick cracking a joke about his longtime pal David Spade ... so it seems he hasn't lost his sense of humor.

Get well soon, Nick!