In the piano store, Luann tells Marge about a hypnotherapist named Dr. Wendy Sage, who had a mastectomy and chose not to have breast reconstruction surgery.
Meanwhile, when Bart's sleeve rips while playing basketball, Jimbo, Dolph, Kearney, and Nelson take him to an underground basement in school where they teach him to get into shape and become a man.
When Bart sees the guys hanging around with their girlfriends, he feels betrayed, runs away from the basement and plays basketball with the other children.
The character of Wendy Sage was created and voiced by Renee Ridgeley, an actress, writer, and real-life breast cancer survivor and the wife of Simpsons writer Matt Selman who said: “While Sage has all the telltale signs of a breast cancer survivor: a visible scar from a port-o-cath (a device used to deliver chemotherapy), curly hair regrowing from chemo treatment, an obviously one-breasted appearance, and is visually concave on her mastectomy side, the episode does not focus on her past disease.
"By living openly as a one-breasted woman, she sends a message of acceptance and wholeness celebrated by individuals in marginalized groups.
[2][4][5] Tony Sokol of Den of Geek gave the episode 4 out of 5 stars, stating "'Lisa's Belly' works because her healing and acceptance comes from the most unlikely of places.
It is the word skeptics use to describe the wacky world of mental health professionals, but it’s also the thing hypnotists are supposed to make their clients do after the most clichéd sessions.
"[6] Marcus Gibson of Bubbleblabber gave the episode a 8 out of 10, stating "Overall, 'Lisa's Belly' continues the show's strength in delivering humorous yet relatable stories that deal with current issues.
This is another episode that provided a healthy balance between comedy and drama in terms of representing real-life problems and mental health.