South Park Episode 415 - "Fat Camp"

Mrs. Cartman holds an intervention for her son's eating problem and is sending him to fat camp.

Cartman returns from camp, 40 lbs. lighter. Cartman is selling candy to the fat kids. Kenny is challenged by the other children to do crazy things for money. Kenny's popularity rises and he soon gets his own TV show. An event happens where Kenny gets inside Ms. Crabtree's uterus for six hours.