Betty White and Carol Burnett have worked together before as sisters, Eunice and Ellen, on the Carol Burnett Show and Mama's Family in the late 70s and early 80s.
The title of the episode is a nod to The Carol Burnett Show's As the Stomach Turns sketches. The sketches were parodies of day time soap operas, and focused on Burnett in the lead role of Marion.
Carol Burnett and Tim Conway (Nick in this episode) worked together in The Carol Burnett Show. (1975-1978) Nick was known to improvise a lot during this show.