(HealthDay) -- People with inflammatory bowel disease, which includes Crohn's disease and colitis, may be at increased risk for flare-ups when they fly or travel to high altitudes for skiing or mountain climbing, a new study suggests.
This complications affected patients with either Crohn's disease (which typically involves the small intestine) or ulcerative colitis (which typically involves the large intestine and rectum), but the risk appears to be higher in those with Crohn's disease, the researchers found.
The study included 103 patients who were seen at inflammatory bowel disease clinics in Switzerland. The 52 patients with flares and the 51 patients who were in remission were asked about their activities during the previous month.
Overall, patients with flares had made many more frequent flights or trips to areas above 6,500 feet.
The study was to be presented Monday at the Digestive Disease Week meeting in San Diego.
In high altitudes, lower oxygen content in the air means that people may not get all the oxygen their bodies are used to getting. People who live at lower altitudes may experience headaches, weakness and other symptoms until they acclimate to the lower oxygen content in the air.
How that might connect to inflammatory bowel disease is unknown, according to researchers. Oxygen depletion in any tissue (hypoxia) causes inflammation, but there are little available data about how hypoxia might exacerbate inflammatory bowel disease, said study author Stephan Vavricka, chief of the gastroenterology and hepatology division at Trieml Hospital in Zurich.
"We need to look more closely at how hypoxia may induce inflammation on a molecular level in the intestines," he said in a meeting news release.
The study was too small to draw conclusions about inflammatory bowel disease symptoms or severity based on whether a patient had been flying, skiing, hiking, climbing or just visiting high-altitude locations.
"It's too early to tell patients not to get on a plane or to restrict where they go," said Vavricka, who plans further research with a larger number of patients.
Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.
Explore further: Research team identifies genes linked to ulcerative colitis
More information: The U.S. Office on Women's Health has more about inflammatory bowel disease.