Brain specialist, Dr David Nicholl said he had seen two such patients in the same week, following obesity health tourism.
The General Medical Council (GMC) has said it will write to the Turkish government over the way British patients are being recruited for surgery.
Dr Nicholl said he has reported to the GMC that patients are being invited to sign up for surgery while attending meetings held in British hotels.
Mr Singhal said obesity health tourism had been made worse by lockdown and even longer waits for NHS surgery in the UK.
Desperate people are visiting Turkey, where treatment is a quarter of the cost of a private operation in the UK.
“Seven to eight years ago, I used to see one complication from Turkey every six weeks, now I am seeing one a week,” said Mr Singhal.
He said the majority are leaks that become infected and over time cause significant difficulties.
Pinky Jolley requires morphine six times a day for the pain she is suffering and has to be tube fed because she cannot eat at all following her surgery in Turkey in November 2022.
‘Pain was excruciating’
In total, she has spent three months in hospital on intravenous antibiotics, had eight CT scans, six endoscopies and one major operation.
She said: “Within moments of waking up, the pain was excruciating.”
“I just knew that something wasn’t right.”
Mr Singhal believes the NHS has had to spend £100,000 on her care, following her cut-price £2,100 operation.
He is examining her after doctors in Liverpool ruled out further surgery.
He said any operation to improve her condition is complex and potentially life-threatening because of the extent of the damage to her gastric system.
The cash she paid for surgery and accommodation would not cover the disposable equipment used during an operation in the UK.
Treating the complications from abroad, is affecting the number of operations that can be done on British patients here, Dr Singhal said.
Dr Nicholl, who works at the same trust, said that in his 22-year career he had never seen neuropathy – damage to a patients nerve endings – caused by obesity surgery.
It occurs when the stomach is too small – a recognised complication from the surgery – and the patient does not get enough vitamins and minerals, he said.
Both the patients he saw had undergone their surgery abroad.
“This can affect a patient’s ability to walk, and sometimes the damage can be irreversible,” he said.
Both doctors are calling for better regulation of bariatric surgery in Turkey.
On the way patients are being recruited, Dr Nicholl said: “It’s a grey area, if a doctor isn’t registered with the General Medical Council, they cannot practice medicine in the UK.”
Dr Singhal said with waiting lists as long as they are, there is no likelihood of stopping people going abroad, but British authorities do need to vet foreign hospitals so patients can have a better idea of where it is safe to go.