For years, we've been encouraged to prevent colon cancer by submitting our bottoms to a colonoscopy. Now, however, comes information that suggests Ontarians who have a colonoscopy performed in a doctor's office or a private clinic are three times more likely to have an incomplete one done than patients who have it done in a hospital.

It's just the type of news that gives consumers another reason not to have the dreaded procedure in which a thin flexible tube with a camera at its tip is inserted into the rectum and threaded up through the entire metre of colon in order to examine it from the inside for cancer growths.

I asked the study's Dr. Linda Rabeneck what was meant by an "incomplete" procedure.

She explained that for a colonoscopy to be complete the doctor has to get the scope all the way 'round to the uppermost part of the colon to see whether there's cancer anywhere along the large bowel.

This study, however, showed that 13% of colonoscopies were incomplete in that for whatever reason the doctor did not get the scope all the way around. When Rabeneck looked at where these incompletes were performed, she found that the number of incompletes and missed colon cancers were higher when a colonoscopy was done at a doctor's office or a private clinic rather than in a hospital.

"We know that approximately 15% of outpatient colonoscopies are done outside of a hospital," Rabeneck told me.

NO REGULATIONS

The Toronto Sunnybrook Regional Cancer Centre gastroenterologist is also a senior scientist at ICES, a non-profit organization that uses population-based information to measure health-system performance.

"When these colonoscopies are done outside of a hospital, there are no regulations in place that relate to the credentialing of the physician, to infection control, to the monitoring that needs to be done, and to what type of resuscitation equipment needs to be available," she said.

This lack of standards might explain why some colonoscopies are not completed -- an unfortunate situation when you consider the horrid "prep" consumed the night before the procedure in the name of cleansing the bowel.

In a hospital environment, standards already in place include a process for reviewing the credentials of a physician, the kind of infection control that's required for the endoscopy suite, and what needs to be done for monitoring patients after they've been given sedation.

LESS EXPERIENCED

There is further speculation as to why some procedures are incomplete, however: The doctors doing them may be less experienced, or the people having them done may not be totally cleaned out.

Or maybe little or no sedation is used and so patients in discomfort ask for the procedure to be stopped.

What is known is that because hospitals have long wait lists for colonoscopies (at one downtown hospital, the wait is at least a year), several doctors have started their own private practices where waiting times are only weeks or a few months.

"It's a growing trend," Rabeneck agreed. "A decade ago, 10% of these procedures were done in private offices. Now it's about 16%."

Though Rabeneck's study did not identify specific places or evaluate what standards the private clinics have already put into practice, she stressed that the issue is that these places are "unregulated."

In her view, colonoscopies performed outside of hospitals in Ontario can be "highly variable in terms of quality."

Her study also concluded that women, seniors and those who've had abdominal or pelvic surgery are at a higher risk of having an incomplete procedure.

So what to do? Try to find out the volume of procedures performed by the doctor (I'd rather have one done by a doc who does 200 a year instead of 50) and try to get a doctor who is a gastroenterologist because this specialty has the lowest percentage of incompletes.

Whatever you do, please have one (your first should be at age 50 or sooner if there's a family history or if you have symptoms).

"We have a huge burden of disease in our province," Rabeneck said. "3,250 people will die of colon cancer this year and 7,800 will be diagnosed.

"There's still an embarrassment factor when it comes to this part of the body," she added.

"But we've got to get past it."