Al Roker -- Slams Conan ... Says TBS Is Like IBS ... And Al Should Know

Al Roker ... who famously crapped his pants at the White House ... took repeated cheap shots at former pal Conan O'Brien ... saying he misses him on "real TV."

Here's the backstory ... Al used to appear frequently on Conan's show back in the day at NBC, but the 2 apparently had a falling out.

So on the Sirius show "Stand Up" with Pete Dominick, Roker got incredibly holier than thou, saying he thought Conan was on "this web thing." Apparently Al doesn't know the web is kinda the future.

Nonetheless ... he then took a shot at TBS, Dominick mentioned that Al had IBS at the White House, and Al dismissively shot back that TBS and IBS are the same thing.