Medicare has reimbursed colonoscopy since 1998, but annually, less than 15 percent of Medicare recipients have the procedure done, mostly because of the prospect of extreme discomfort.

"A lot of patients are very scared they will have a horrible experience," says James Church, MD, a colorectal specialist at the Cleveland Clinic. "Doctors' attitudes toward sedation vary; some won't use it at all, others totally sedate the patient. We need to make patients feel confident they won't experience a lot of pain."

For the physician, colonoscopy is technically challenging; negotiating the sigmoid colon and straightening the colonoscope can be difficult. And the procedure is time-consuming, taking from 30 to 60 minutes. Manufacturers and researchers are responding to physician and patient concerns with improved technology and techniques. Here's an overview of what's new and what you can expect.

Improved vision field
This year, Fujinon plans to introduce the high-resolution Honeycomb Super CCD colonoscope, which enables surgeons to see more (Fig. 2). Forty-five-degree-angled pixels and octagonal photodiodes enhance vision. With Honeycomb CCD, a physician can clearly see an image as small as 4.4 microns (.004 millimeters). Fujinon says this offers three times the resolution of a scope without Hon-eycomb CCD, and the image resolution is captured in real time (30 frames per second).

Adjustable scope stiffness
In 2000, Olympus introduced Variable Stiffness Colonoscopy (VSC). The colonosocope is equipped with an adjustment knob to increase or decrease stiffness, which assists the physician in driving through a tortuous sigmoid colon, around the splenic and hepatic flexures and to the cecum more efficiently. (See Fig. 3)

"A more rigid scope makes it easier to intubate into the cecum and small intestine. It's a nice 'bell and whistle' that allows successful completion in more difficult cases, such as chronic constipation," says colorectal surgeon Mark Gilder, MD, of St. Barnabas Hospital in New Jersey.

Although this feature is designed to save time, a recent study published in Gastrointesinal Endoscopy reported that VSC was, on average, just one minute faster than using a conventional colonoscope. VSC will cost $2,000 to $3,000 more than a conventional scope and requires more maintenance.

Virtual scoping technique
Virtual colonoscopy is a great idea, but the technology has not arrived quite yet, experts say. In this procedure, the entire colon is imaged on computer using a fast CT-scan method. In a study of 300 patients at University of California at San Francisco who underwent a virtual colonoscopy, followed by a standard colonoscopy, the virtual procedure detected 90 percent of all large polyps. But doctors say it's not so successful at detecting small polyps.

"With virtual colonoscopy, the patient still needs to be prepped (with dye) and insufflated with air. If a polyp is found, the patient still might need an actual colonoscopy. Virtual colonoscopy cannot detect small or medium polyps. The patient might as well have actual colonoscopy to start with," says Peter Marcello, MD, a colorectal specialist for the Lahey Clinic, Burlington, Mass.

The virtual procedure has its advantages: Patients do not have to be sedated or put under anesthesia, and the colonoscopy can be performed in less than one minute. So it may work best as a complement to an actual colonoscopy.

"This technique would not completely replace conventional colonoscopy, but it would eventually increase the number of patients who are screened for colon cancer who would otherwise go unscreened," says Judy Yee, MD, an assistant professor of radiology and the chief of CT and gastrointestinal radiology at UCSF.

Better visual differentiation
Optical coherence tomography (OCT) is another "virtual" procedure that holds promise. A dye is applied to the colon, and then the colon is visualized via magnifying colonoscopy. The idea is to differentiate tissues according to the way they reflect light.

"You could do a biopsy without a biopsy," says Dr. Church. "When you find a polyp, you don't know if it's benign unless you do a biopsy. With OCT, we may be able to differentiate cancerous or precancerous tissue just in the way it reflects light."

Real-time scope viewing
Olympus' ScopeGuide, the first endoscope insertion tube system that enables physicians to see - without the risk of X-ray exposure - the shape of the scope from the outside during an endoscopic exam, is ideal for use in difficult colonoscopies, according to the company (Fig. 4).

The ScopeGuide's endoscope contains small coils that generate magnetic fields, which are detected by the system's main unit. From this data, the computer reconstructs a schematic picture of the endoscope on the monitor, the company says. That way, the physician can see the scope at all times - in 3D and real time.

According to Olympus, using the ScopeGuide will potentially result in shorter insertion time, faster access to the cecum, and minimized loop size or elimination of loops.

Non-human scope help
Robotics may revolutionize colonoscopy. Calif.-based Neoguide Systems is developing a colonoscope that uses robotic technology to navigate the colon and that conforms to the body's natural geometry. Neoguide says this device will be easier to use, cheaper, safer, faster and less unpleasant for the patient. Future generations of its colonoscope may incorporate diagnostic sensors and analytic devices.

Elective stent insertion
New surgical techniques are helping the sickest patients. Dr. Gilder performs intraluminal intervention on patients with near-complete large bowel obstruction. In this procedure, the surgeon uses a colonoscope to place a stent in the colon (Fig. 5). Like a cardiac stent, the colonic stent restores patency, relieving the obstruction. Thus the surgeon better prepares the patient for surgery or, in the case of widespread metastasis, enacts a permanent solution.

"The use of a stent transforms an emergency procedure into an elective one. This technique was first used in 1999, but the technology and delivery system has improved so that more surgeons can utilize it," says Dr. Gilder.

Non-invasive genetic mapping
DNA analysis of stool specimen is a non-invasive screening test that may make catching small, abnormal polyps easier, and could eliminate the need for screening colonoscopy. Researchers at the Mayo Clinic studied DNA from polyp cells, exfoliated into stool taken from cancer patients. They found the DNA differs from that of benign polyps, and researchers identified cancerous cells 91 percent of the time.

"If this becomes a viable test, we could identify cancerous polyps just from testing the stool. If we find the abnormal DNA, we can then perform colonoscopy and remove the polyp," explains Dr. Marcello. He adds that now, colonoscopy can miss tiny polyps. DNA analysis will catch all cancerous polyps, no matter how small.

Expanded procedure demand
Improvements in equipment and colonoscopy techniques are making the procedure faster, easier and more comfortable. And as colorectal cancer statistics have become more available, physicians, insurers and the general public have become increasingly aware of the value of colonoscopy. Add it all up, and the demand for time from colorectal surgeons is likely to increase in outpatient procedure rooms and ORs.

"The question is whether we have enough experienced colonoscopists to meet the demand," says Dr. Church.