The tribunal also heard how Mr Gilbert is said to have made racist comments when talking about people from Africa.
Finding his fitness to practise impaired because of misconduct, tribunal chairman Andrew McLoughlin said he had “taken a number of steps to remediate his failings”.
But he concluded that Mr Gilbert’s “insight” was “not fully developed into the full extent of his behaviour”, and he would “benefit from further time to digest and reflect on the findings”.
Mr Gilbert has 28 days to appeal against the suspension.
He was the chief medical officer overseeing The New Foscote Hospital in Banbury, Oxfordshire, and the Royal Buckinghamshire Hospital in Aylesbury but left after the hearing.
The private hospitals also carry out NHS hernia waiting list clinics and surgeries.
Dr Andrew Brent, chief medical officer at OUH, said: “With the conclusion of these proceedings, I would like to thank staff who stood up and called out unacceptable behaviour.
“They have had to revisit this a number of times and we recognise how difficult that must have been.
“We will continue to offer our staff support and to encourage all our people to feel able to challenge behaviours that do not fit with our organisational or professional values.”