Prevalence, comorbidity, and risk factors for functional bowel symptoms: a population-based survey in Northern Norway

To assess the occurrence of functional bowel (FB) symptoms in Northern Norway, and to describe gender differences, comorbidity, and association to risk factors, including Helicobacter pylori infection.

Adult subjects (18-85 years) from the communities Bodø and Sørreisa were invited to complete a questionnaire on gastrointestinal symptoms, and to provide stool samples for assessment of H. pylori.

Of 3927 invited subjects, 1731 (44.1%) responded to the questionnaire and 1416 (36.0%) provided stool samples. Functional bowel symptoms were found in 25%, somewhat more frequent in females (28.6%). Symptom pattern differed between genders only with regard to constipation. Presence of FB symptoms was significantly associated with gastroesophageal reflux symptoms, headache, dizziness, palpitations, sleep disturbances, and musculoskeletal symptoms. Psychometric traits were also more prevalent: feeling of low coping ability, feeling depressed, feeling of time pressure, and a low self-evaluation of health. In a multivariate regression model, factors that influenced the reporting FB symptoms were male gender (OR 0.71, 95% CI (0.52; 0.96)), age 50-69 years or ≥70 years (OR 0.49 (0.30; 0.80) and 0.40 (0.21; 0.79)), obesity (OR 1.61 (1.05; 2.47)), NSAID use (OR 2.50 (1.63; 3.83)), and previous abdominal surgery (OR 1.54 (1.05; 2.26)). The presence of H. pylori was not associated with FB symptoms.

Functional bowel symptoms are prevalent, but our findings may be prone to self-selection bias. FB symptoms carry a significant burden of comorbidity. Female gender and low age are known risk factors for FB symptoms, whereas NSAID use as a risk factor deserves further clarification.