Prince Philip, Queen Elizabeth II's husband, is undergoing an exploratory operation after experiencing abdominal pain, reports Sky News.

The 91-year-old British royal consort was admitted to the London Clinic, a private hospital, on June 6, where he is expected to remain for about two weeks, according to a statement from officials at Buckingham Palace.

Prince Philip's operation will take place on Friday, June 7, just days before his 92nd birthday on June 10.

The chief spouse, known officially as the Duke of Edinburgh, was entertaining guests at a Buckingham Palace garden party earlier in the day. He was driven to the hospital in his own car, and was well enough to walk into the building on his own, according to Reuters.

Queen Elizabeth II had awarded him with New Zealand's highest honor, the Order of New Zealand, in an official presentation that marked the Diamond Jubilee that morning.

Guests at the following afternoon garden reception noticed no signs of illness, according to Sky News, and observed the Prince cracking jokes in a relaxed manner with other attendees.

He had missed a palace engagement on the evening of June 3 after temporarily losing his voice, said a Buckingham palace spokesperson, but that illness was unrelated to the scheduled operation.

The spokesperson said that Prince Philip's hospitalization had been scheduled in advance, and was not an emergency.

"He is in very good health," she told Sky News, and asked the media to refrain from speculating about the cause of Prince Philip's operation.

Prime Minister David Cameron took to Twitter to express his support for Prince Philip during his hospitalization.

My best wishes to the Duke of Edinburgh who is in hospital tonight. I hope he has a swift recovery.

— David Cameron (@David_Cameron) June 6, 2013

Prince Philip has been through several publicly acknowledged hospitalizations in the past two years, including one for a blocked heart artery in December 2011 that had him bedridden throughout Christmas.

He also needed treatment for a bladder infection in June 2012, which put a damper on celebrations of Queen Elizabeth II's Diamond Jubilee, and was readmitted to the hospital when it flared up again two months later.

How Can an Operation Assess Abdominal Pain?

Abdominal pain can have many potential causes, since so many organs like the stomach, intestines, pancreas, gallbladder, and appendix are packed tightly in the abdominal cavity.

While less threatening problems like irritable bowel syndrome, appendicitis, or gastroesophageal reflux might cause it, pain in the abdomen can also indicate more serious conditions like abdominal aortic aneurysms or cancerous tumors.

Dr. Arun Ghosh told the Daily Mail that Prince Philip's operation will probably involve a laparoscopy, also known as keyhole surgery, under general anesthesia.

In that procedure, a hollow flexible tube with a miniature video camera and high-intensity light attached at the end is inserted into a cut below the patient's navel, allowing surgeons to directly view the contents of the patient's pelvis and abdomen on a screen.

Diagnostic laparoscopy can help doctors identify abdominal obstructions or growths that cause pain and discomfort, providing more detailed visuals than non-invasive imaging methods like ultrasounds or x-rays.

The procedure typically takes up to an hour, and patients feel no pain when anesthetized. They can be given pain medications to relieve aches and soreness afterward.

Unless serious complications are revealed during the exploratory operation, Prince Philip is likely to spend at least several hours recovering from the laparoscopy in the London Clinic before he's well enough to return home to Buckingham Palace.

Because he's so old, however — and a member of the royal family, to boot — doctors will probably want to keep him in the hospital a bit longer for observation.

Source:

Bhimji S. Diagnostic laparoscopy. Medline Plus. 2012.

Heller JL. Abdominal pain. Medline Plus. 2011.