A four-week-old baby girl made medical history at St George’s Hospital after becoming the youngest child in the world to have keyhole surgery for appendicitis.

Isabel Dolby, from Raynes Park, spent the first few weeks of her life in agony, with doctors baffled as to what was wrong until they took her to the operating theatre.

Throughout the world there have been just 100 recorded cases of appendicitis in babies during the last hundred years, with only two thirds surviving the open surgery.

Her mum, Candice, 33, said: “We were extremely worried. It was two weeks of poking and proding and having scans. Everything was inconclusive.

“Nobody knew what was wrong with her. The only option was to take her into surgery and see.”

The problems began with what looked like a milk rash, but it steadily got worse and her stomach became swollen and hard.

Staff at Kingston Hospital’s Accident and Emergency department carried out blood tests, a lumbar puncture and an x-ray, but there was no clear sign of what was wrong.

She was transferred to the paediatric unit at St George’s where more tests were carried out before experts decided to send her for surgery.

Three hours later, Mrs Dolby and her husband, Richard, 36, were told she had acute appendicitis.

Zahid Mukhtar, a paediatric consultant at St George’s who led the operation, said keyhole surgery had only recently become possible for babies, as the equipment is getting smaller and better.

He said: “Minimally invasive techniques such as keyhole surgery are far better for babies, because they recover more quickly. Isabel made a remarkable recovery and the only remaining signs that she had surgery are two small marks on her stomach, a few millimetres across.”

His team used the latest miniaturised technology, including a tiny endoscopic camera, to operate.

Now she is a healthy toddler back at home with her older brother, Oliver, who is two.

Mrs Dolby said: “St George’s Hospital was absolutely brilliant and Mr Mukhtar’s team were outstanding. I’m so grateful that she’s back to her normal self.”