It is thought the intestinal damage could have been caused by hunger and stress.
The 15-year-old's body was discovered on Tuesday, nine days after she disappeared from an eco-resort she was staying at with her family in Malaysia.
The forensic doctor who carried out the post mortem said he believed the schoolgirl had died six days after she went missing, and that there was no evidence she had been abducted or raped.
Nora, who was born with learning difficulties, was reported missing from her family's holiday resort near Seremban, around an hour south of capital Kuala Lumpur, on August 4.
Here is everything that has happened in the search for Nora:
August 4: Nora is reported missing after her father discovers she is not in her bedroom at the Dusun Resort at around 8am on Sunday.
The window was also open in the room that Nora had been sharing with her two siblings.
Family friend Catherine Cook says it is "out of character for Nora to go wandering off".
August 5: The Lucie Blackman Trust says that Malaysian police are treating Nora’s disappearance as a potential abduction, but officers deny there is any foul play involved.
However, speaking to press on Monday afternoon, Che Zakaria Bin Othman, deputy police chief of Negeri Sembilan, says: “So far there’s no indication of foul play, however investigations are still ongoing.”
August 6: Nora’s family say they believe she has been abducted.
In a statement they continue: "We are especially worried because Nora has learning and developmental disabilities, and is not like other 15-year-olds.
“She looks younger, she is not capable of taking care of herself, and she won’t understand what is going on.
“She never goes anywhere by herself.
"We have no reason to believe she wandered off and is lost.”
August 7: Police say they are analysing unidentified fingerprints found in the family’s hotel suite.
The prints were at an open window in a downstairs hall, not in the bedroom upstairs where the girl was sleeping with her siblings, deputy police chief Che Zakaria Othman says.
August 9: Police investigate whether footprints found in the forest where Nora went missing belong to the teenager.
State fire and rescue department assistant director Ahmad Mukhlis Mokhtar tells journalists: “Previously, our detective canines had spotted footprints, but when we conducted a search there, we couldn’t find her.”
Nora’s family also reveal more about her condition, holoprosencephaly, a failure of the brain to develop properly during pregnancy, meaning she needs help with everyday aspects of life.
Search crews also play recorded messages from Nora's mother, Meabh, through the forest in an attempt to reach the youngster.
The family say in a statement: “Nora is not like other teenagers. She is not independent and does not go anywhere alone.
“Nora can read like a young child, but she cannot write more than a few words.
"She has a good memory but she cannot understand anything conceptual.
"She is unable to do maths and so things like money are impossible to manage.
“She cannot make or receive phone calls independently.”
August 10: Nora’s family thank the search teams involved since the teenager’s disappearance.
Her mother and father, Meabh and Sebastien Quoirin, say: “To be with us here, it means the world to us.
"We are so grateful for everything that you are doing for us, everyone who is helping here and not from here.
“We are extremely impressed by the effort, your expertise, your dedication and we hope you find Nora.
“And thank you so much.”
August 11: Nora is missing for a week, with hundreds of rescuers still involved in the search operation.
August 12: A visibly emotional Ms Quoirin makes a further appeal for her daughter to return home.
She tells television reporters: “Nora is our first child.
“She has been vulnerable since the day she was born.
“She is so precious to us and our hearts are breaking.
"We are appealing to anyone who has information about Nora to help us find her.”
A reward of £10,000 – donated by an anonymous Belfast business – is made available for information leading to Nora’s safe return.
August 13: A body is found in the search for Nora, the Lucie Blackman Trust confirms, saying it “seems likely” it belongs to the school girl.
Investigations are under way to confirm the body’s identity and the cause of death.
The family of Nora confirm the body found near to the resort in Malaysia where they had been staying was her.
"She is the truest, most precious girl and we love her infinitely.
"The cruelty of her being taken away is unbearable.
"Our hearts are broken."
A post-mortem examination is due to take place to establish the cause of Nora's death.
They say the post-mortem examination showed she died from intestinal bleeding due to starvation and stress, and that she had died two or three days before she was found.