THURSDAY, Oct. 20 (HealthDay News) -- Researchers report that following surgery, people with inflammatory bowel disease (IBD) may be at increased risk for blood clots known as deep vein thromboses and pulmonary embolisms.

Deep vein thrombosis (DVT) is a blood clot in a deep vein in the thigh or leg -- it's best known as "economy-class syndrome," after cases that occurred in passengers on long-haul flights. DVTs can travel to the lungs and lead to dangerous clots there known as pulmonary embolisms (PE).

"An increased risk of DVT and PE in patients with IBD has been evident for the past 75 years," co-authors Dr. Andrea Merrill of Massachusetts General Hospital and Dr. Frederick Millham of Newton-Wellesley Hospital, both in Boston, wrote in the study published in the Oct. 17 online edition of the journal Archives of Surgery.

However, they added that "most work in this area has not looked specifically at patients undergoing surgery." Because surgery is common for people with IBD, getting a better idea of their level of risk for these clots is important, the researchers said.

According to the American College of Family Physicians, over 600,000 Americans suffer from IBD, which involves a chronic inflammation of the intestines. Crohn's disease and ulcerative colitis are two common forms of IBD.

In their study, Merrill and Millham looked at data from over 2,200 IBD patients and almost 270,000 patients without IBD who had surgery at 211 U.S. hospitals in 2008.

Overall, there were 2,665 cases of DVT or PE (1 percent), but the rate among patients with IBD was more than double, at 2.5 percent.

Interestingly, surgeries in locations away from the intestines had an even higher rate of DVT or PE for people with IBD -- 5 percent, the investigators found.

Rates of post-surgical heart attack or stroke were not different in IBD patients versus those without the illness, the team noted in a journal news release.

The researchers concluded that "patients with IBD who undergo surgery have a twofold increased risk of DVT or PE. In patients with IBD who are having nonintestinal surgery, this risk may be even higher. These findings suggest that standard DVT and PE prophylaxis [prevention] should be reconsidered for this patient group."

One expert said the new finding may have an impact on clinical practice.

"Current guidelines do not recommend routine DVT and PE prophylaxis in patients with IBD undergoing surgery," said Dr. David Bernstein, chief of the division of gastroenterology at North Shore University Hospital in Manhasset, N.Y.

However, he said that "the data presented in this study begs the question that perhaps the approach to prevention of DVT and PE in IBD patients undergoing routine, non-emergent surgery needs to be reassessed."

More information

There's more on inflammatory bowel disease at the American Academy of Family Physicians.