A man from Borehamwood was left screaming in agony during an operation when doctors failed to sedate him properly.

Anthony Fraser, 46, had to be held down by four hospital staff as he begged doctors to stop during the procedure at Edgware Community Hospital on Monday.

Doctors looking for signs of Crohn's Disease were giving Mr Fraser a colonoscopy: an exploratory procedure where a small camera was inserted up his anal passage, through the colon and small intestine to his stomach.

Before undergoing the operation, he was told by the anaesthetist that he would be sedated he would not feel anything or remember anything about it when he woke up.

But Mr Fraser was wide awake throughout the entire procedure and pleaded for doctors to stop.

"I was in total agony," he said.

"I've never known pain like that in my life it was absolutely excruciating."

"I kept telling them to stop but they didn't. They just kept telling me it would only be another couple of minutes. It was complete torture."

Doctors inflated Mr Fraser's stomach with air so they could get a clearer picture of what was going on. As he wriggled, two nurses pressed down onto his stomach, while another two people held his arms down as he screamed.

"It's an absolute ridicule. I couldn't quite believe what was going on and still can't understand what happened.

"Why couldn't they inject me with some more sedative or have the common decency to stop?"

After the operation, which took just over half an hour, Mr Fraser had something to eat and left.

"I just wanted to get out of there as soon as I could," he said. "I didn't want to stay a moment longer.

"The nurse called me yesterday to check I was okay. When I told her what happened, she couldn't believe it. She said I shouldn't have remembered a thing but I could recount the entire procedure."

Milly Fraser, Anthony's mother, who was at the hospital at the time, said: "We just couldn't understand it. The man before him who had exactly the same procedure just before him, came out all dozy and disorientated.

"It was very traumatic for Anthony he wasn't like that at all. He just looked as white as a ghost."

Martine Sanders, communications director for Barnet Primary Care Trust, which runs the hospital said: "Because of patient confidentiality, we cannot comment on a patient's individual treatment.

"However, we can confirm that generally a patient undergoing endoscopy or colonoscopy will usually have sedation and some analgesia if required. However, this would depend on the specific circumstances of an individual.

"If the patient in question is unhappy about the way their procedure was carried out, we would advise that they contact us directly and we will be very happy to look into their concerns."

Mr Fraser said he was diagnosed with Crohn's Disease six-and-a-half years ago, but was recently told doctors were unsure if he still had it.

Crohn's Disease is a disease of the bowel, causing inflammation of the small intestine which can cause pain, making the intestines empty frequently, resulting in diarrhoea and severe weight loss.

There is no cure for Crohn's Disease, but it can be treated using drug therapy, nutritional supplements such as high-calorie liquids, and surgery to remove part of the intestine.