Emma Coronel Aispura, a former beauty queen and a U.S. citizen who lives in Mexico, spent several days in Washington, where she held a meeting at the Inter-American Commission on Human Rights, an arm of the Organization for American States.
A spokeswoman for the commission, Maria Isabel Rivero, confirmed the meeting with Aispuro but, citing privacy issues, would not discuss the purpose or details of the visit.
"Every single person who asks for a meeting at the IACHR is received under rules of confidentiality for the security of the persons involved," she said.
U.S. officials questioned Coronel during her entry and departure from the U.S. as part of the customs process, according to a U.S. official. But the dual U.S. and Mexican citizen is not charged with any crimes, so she was allowed to enter and leave.
Andres Granados, an attorney for Guzman, told CNN in a telephone interview that the purpose of Coronel's visit was to file a petition with human rights commission and to seek an investigation into the conditions of his imprisonment in Mexico.
In February, Coronel told Spanish-language broadcaster Telemundo she feared for her husband's life in Mexico's Altiplano prison, saying, "They want to make him pay for his escape."
"They say that they are not punishing him. Of course they are," Coronel said. "They are there with him, watching him in his cell. They don't let him sleep. He has no privacy, not even to go to the restroom."
Mexican authorities, citing security concerns, have since moved Guzman to a prison in Juarez, Mexico, near the U.S. border.
Granados says Coronel noticed being followed during her visit by what she assumes to be U.S. government agents.
"That's how it is for her, she knows they always have her under surveillance," Granados told CNN.
Coronel, more than 20 years Guzman's junior, met the drug kingpin when she was just 17, in 2007, and they were married the following year. She gave birth to twin daughters in Lancaster, California, in 2011. She was with her husband when he was arrested in the Mexican resort town of Mazatlan in 2014.