What really happened to Heather O’Rourke?
Several medical specialists and even her manager were puzzled by cause of death. It was not congenital, present from birth, that’s for sure.
https://apnews.com/article/fe8cdc53f37125b6b3a01063a5091e11
The article claims there was no prior indication of intestinal troubles, but other sources indicate O’Rourke was being treated for Crohn’s Disease before her death. Because she was believed to have Crohn’s, she wasn’t tested for other issues. Her facial features were puffier than usual in Poltergeist 3, due to the steroids she was receiving.