Chris Hartley's stomach has been twisted in nausea and bouts of sharp pain for the past year. Doctors have tried everything to find out why.

Once they pushed a long, flexible tube with a camera called an endoscope down his throat and eventually into the top portion of his small intestine to look for an ulcer, lesion or tumor. They used the same approach to study the large intestine in a procedure called a colonoscopy.

When nothing showed up, they resorted to a battery of CT scans. Still no luck.

So on Monday, Hartley swallowed a camera. The pill-sized device took more than 100 images a minute as it moved naturally through his digestive system. The innovative approach may help him avoid exploratory surgery.

"It was the easiest test I've had," the 42-year-old Kissimmee carpenter said. "If they didn't have this pill, the only thing left to do would be to open me up."

Today, the pill is approved exclusively to study the small intestine. Much of that organ is inaccessible by current probing techniques, and X-rays or other imaging methods can miss trouble spots.

But the camera can get close-up views of the snug passageways inside the 20-foot organ. It does not work as well in the wider channels of the large intestine.

The current pill cannot replace colonoscopy, although doctors expect future generations of the device to be used on the entire digestive system. For example, the large intestine might be studied by remote-controlled cameras that can be maneuvered more precisely around the organ.

For now, doctors are impressed with the existing camera's views of the small intestine. Two Orlando-area physicians recently started using the $450 pills, both on two patients apiece so far. They think interest in the technology will increase dramatically as word spreads.

"We're now able to journey to the center of the body to an area that was previously difficult to evaluate," said Dr. Ira Shafran, one of two Florida Hospital gastroenterologists using the camera. "Being noninvasive, this particular technology is an outstanding way to get clear pictures of the small intestine with no pain and no risk for the patient."

The camera pills are made by an Israeli-based company, Given Imaging, which began developing the technology in 1998.

Pill works for 8 hours

Before taking a pill, patients must stop eating or drinking at midnight the day before their tests. The patient then swallows the pill, which works for about eight hours before running out of battery power. It ultimately is passed naturally from the body.

While it's working, the patient wears a small receiving device on his or her belt, and the camera transmits images to it for storage. The person is free to move about as usual but cannot eat or drink much for the duration of the test.

Hartley was allowed a light lunch and one glass of water Monday. He swallowed the pill at 7:45 a.m., went about his day, then returned to Florida Hospital Celebration Health about 4 p.m. It takes a couple of hours for the images, which number about 50,000, to be downloaded onto a computer.

A doctor then needs a couple of hours more to examine the photos. In early tests of the device, the camera was 70 percent effective in finding the source of trouble, Shafran said.

Meanwhile, a new study is under way at Mount Sinai Medical Center in Miami to further evaluate the camera's effectiveness. Potential drawbacks include the possibility that the camera could get stuck inside the small intestine -- perhaps on a protruding tumor that is causing the patient's problem. Surgery would be needed to remove it.

Also, unlike surgery or use of the endoscope, the pill does not allow doctors to collect tissue samples from the small intestine. More procedures still are needed for that.

"You can't biopsy a Polaroid," said Dr. Jamie Barkin, professor of medicine at the Miami University School of Medicine and chief of gastroenterology at Mount Sinai.

Lack of absolute precision

Additionally, doctors do not have absolute precision in determining the location of an image. They have to make an assumption based on the time the photo was snapped and the camera's expected position at that point.

"There is no marker externally to verify where the capsule was, so it does leave a little bit of guesswork, this is true," said Dr. Badar Anwer, a gastroenterologist at Celebration Health who is treating Hartley.

Overall, though, doctors say the camera is an incredible resource for studying the small intestine. Anwer estimates he will be using it on two or three patients a week to start, and Shafran already has 20 additional patients booked for the exam.

Doctors at Orlando Regional Medical Center have placed orders for the pill and its accompanying equipment. Compared to other kinds of digestional tests, the pill will be easier to swallow.

"We've never had a really good way of looking at the small bowel before," said Dr. Raymond Cottrell, head of ORMC's department of endoscopy and gastroenterology. "This miniaturized camera is going to let us look at the small intestine in a way wenever have before."

Robyn Suriano can be reached at rsuriano@orlandosentinel.com or 407-420-5487.