The adult male passenger smeared excrement along the walls in a couple of bathrooms, took off his shirt and attempted to stuff it in the toilet, airport police said.
The FBI and airport police interviewed the passenger, and he was taken to Providence Hospital for a psych evaluation, according to KTVA.
The flight landed in Anchorage about 6:30 p.m. and was met by local and federal law enforcement, police said.
A passenger on a United Airlines flight from Chicago to Hong Kong forced the plane to undergo an unscheduled landing Thursday in Alaska after he allegedly caused a lot of poop to go to unintended destinations. There were more than seven hours left in the planned 16-hour flight when the emergency landing had to be made.
The identity of the man who caused the disturbance has not been released, KTUU reports, but he cooperated with airport police and Federal Bureau of Investigation agents who questioned him after the plane landed in Anchorage.
No criminal charges have been filed.
Airport Operations says the Boeing 777 was grounded overnight for maintenance, leaving passengers stranded in Anchorage.
No one was injured during the incident, KTUU reports.
The F.B.I.in Anchorage confirms that it was notified that a United Airlines flight was involved.