The stone had to be surgically removed from her intestines.
The woman is believed to have swallowed a 6 carat diamond at the Fair in order to smuggle it out, swapping the real stone for a fake one at the booth.
Security cameras recorded it and she was later caught at the Bangkok airport with another man who was travelling with her.
The woman initially denied the theft, and an X-ray was performed which revealed the diamond lodged inside her.
The laxatives given,k failed to work and a colonoscope was used to extract the diamond.
The operation took about 12 minutes and the woman was recovering in hospital.
Smuggling goods by swallowing them is not uncommon.
In 2012, police arrested a 25-year-old man in South Africa who swallowed 220 polished diamonds in order to smuggle them out of the country. They were estimated to be worth approx. $2.3 million, and were discovered by a body scan at the airport as the man was waiting to go through security near Johannesburg o his way to Dubai.