Ponting, who averaged 16.14 runs in the series, aggravated the problem during the fourth Test in Melbourne, further displacing the bone fragment.

BBC: Cricket World Cup: Ricky Ponting makes nets return

They exposed gliadin to digestive enzymes in test tubes and were able to identify a protein fragment made up of 33 amino acids that was resistant to further digestion and whose structure was known to be toxic.

BBC: Cause of dietary disorder uncovered