Experts have thought that about one in four patients with diverticulosis would eventually develop diverticulitis. But a new study suggests the actual risk may be much lower. "The little pouches that form in the wall of the colon are incredibly common and with the increased emphasis on preventive care we do a lot of colonoscopies," Dr Brennan Spiegel told Reuters Health.
"We find a lot of people who have these sacs
in their colon." Spiegel, who was the senior author of the new study, is an
associate professor of medicine at the David Geffen School of Medicine at the
University of California, Los Angeles. Fewer than 5% of adults under age
40 have these pouches, but by age 85, more than 65% of people are affected.
More reliable statistics
Spiegel said that very little is actually known about the normal behaviour of
these pouches. But when a pouch does become inflamed, "it can be serious
and might need surgery to fix. At the very least it requires
antibiotics and some intensive medical therapy," he said.
Doctors have accepted the idea that one-quarter of patients with these pouches would eventually develop inflammation.
"The text books and review articles that go back to
the 1940s all say the same thing, that if you have one of these pouches in your
colon then there's up to a 25% chance that it can become infected or
complicated or even rupture," Spiegel explained.
But this notion of a 25% rule didn't make sense to his team – it seemed too high. "If that
were true, our hospitals would be absolutely overflowing with people with
diverticulitis, and they're not," Spiegel said.
He and his colleagues
wanted a better sense of the real numbers in order to provide more reliable
statistics to newly diagnosed patients.
No symptoms
To learn more, they studied 2 222
patients from the Veterans Affairs Health System in Los Angeles who had been
diagnosed with diverticulosis. None of the patients had any symptoms of the
condition when it was diagnosed; instead, doctors noticed the pouches while the
patients were having a colonoscopy for some other reason.
Using information
from medical records, Spiegel's team tracked these patients for an average of
almost seven years and published their findings in
Clinical Gastroenterology and Hepatology.
Of those 2 222 patients, 95 (4.3%) developed diverticulitis. Not all of those cases were actually
confirmed by a CT scan, however, so the researchers couldn't be sure the
patients' symptoms were actually from an inflamed pouch. When the researchers
counted only cases that were confirmed by a CT scan or during an operation,
only 23 patients (about 1%) actually developed diverticulitis.
The
researched also discovered that patients who were diagnosed with diverticulosis
at a younger age had a higher risk of developing diverticulitis, compared to
patients in whom the pouches were diagnosed later in life.
Adding fibre
The study was
supported by Shire Development LLC. Shire, a pharmaceutical company, was at one
point trying to develop a drug to treat diverticulitis. There were some
limitations to the study.
For instance, most of the patients were male. The
authors say, however, that other studies have shown that the risk of
diverticulitis is similar in men and women.
Also, they admit, some of the information in patients' medical records may have been inaccurate. Spiegel hopes his new research leads to some changes in how physicians treat diverticulosis, adding that current suggestions to add fibre and avoid things like nuts, seeds and popcorn aren't evidence-based.
"The next steps are dissemination of this information, rewriting textbooks and re-educating physicians so they can have rational evidence-based discussions with patients so they don't feel like the sword of Damocles is hanging over their head because they've been given this diagnosis." Spiegel said.
Picture: Diverticulosis from Shutterstock