Police said Karr appeared nervous ahead of his deportation, but "generally he is fine," immigration police chief Lt. Gen. Suwat Tumrongsiskul told the Associated Press.
"We treat him well since he is a high-profile suspect. Yesterday he said that he wanted to eat American food so we ordered from Kentucky Fried Chicken for him, but this morning he had the standard breakfast," of Thai food, Suwat said.
A staffer at the clinic, who spoke on condition of anonymity, said Karr had consulted the doctor about a sex-change operation.
Bangkok is regarded as a global center for sex change operations, which cost a fraction of the price charged in Western countries.
Karr was arrested in Thailand on Wednesday, a day after he began teaching second grade in Bangkok, Boulder County District Attorney Mary Lacy said.
According to ABC News, Karr, dressed in a shirt and tie, said nothing as he was ushered from his Bangkok jail cell into a van to take him to his Thai Airways plane for the 15-hour flight. U.S. guards will serve as his escort.
Karr is then expected to be flown to Boulder for police questioning and another test for DNA, which is seen as being key to the case. The results of a DNA swab taken in Bangkok were not immediately known.
Meanwhile, JonBenet’s father, John Ramsey, is dealing with renewed attention from the press since Karr’s revelation. (Mother Patsy Ramsey died in June, of ovarian cancer.)
This weekend Ramsey was trailed by camera crews as he took his son to college at Purdue University, said longtime family attorney Lin Wood.
"He cannot go back to his home in Michigan because it is surrounded by the media," Wood said. "Last night, I've never heard him so angry. He is upset. He is worried about his son's physical safety."