'Stolen' diamond surgically removed.
She is thought to have swallowed it in order to smuggle it out of the country.
The woman is believed to have stolen the six-carat diamond from a jewellery fair on Thursday by swapping it for a fake gemstone.
However, she was caught on security cameras at the fair and later arrested at Bangkok's Suvarnabhumi Airport.
A man travelling with her was also arrested.
Police said the woman initially denied involvement, but an X-ray revealed the diamond lodged inside her.
She was initially given laxatives, but when nature failed to take its course, a colonoscope was used to extract the gem.
Pol Maj Gen Sanit Mahathavorn, quoted by the Bangkok Post, said the operation had taken about 12 minutes and the woman was recovering in hospital.