The prevalence of headache is higher in people with gastrointestinal (GI) symptoms such as nausea, acid reflux, diarrhea, and constipation, than in people who don’t have these bothersome symptoms, new research indicates.

Both headaches and GI symptoms are common in the general population and eat up substantial healthcare dollars, note the researchers. “However, the scientific literature about the comorbidity of headache and gastrointestinal complaints is scant,” they point out in the medical journal Cephalalgia.

To investigate, Dr. Anne Hege Aamodt and associates from the Norwegian University of Science and Technology, Trondheim, reviewed questionnaires completed by 43,732 participants in the Nord-Trondelag Health Study, including information on GI symptoms as well as headache.

After adjusting for gender, age, depression, anxiety and other factors that might influence the results, the research team noted a significantly higher prevalence of headache among participants with reflux, diarrhea, constipation, and nausea, compared to those without such complaints.

“The association between headache and gastrointestinal complaints increased markedly with increasing headache frequency,” Aamodt told Reuters Health.

These results have implications for the treatment of headache patients. “It is important to consider the total burden of discomfort in these patients and to avoid headache medication with adverse gastrointestinal effects in those with much gastrointestinal discomfort,” Aamodt said.

The strong ties between frequent headache and frequent GI complaints raises questions about common mechanisms that make headache sufferers predisposed to GI complaints, Aamodt also noted.

SOURCE: Cephalalgia, February 2008.