Comorbidity of irritable bowel syndrome in general practice:: a striking feature with clinical implications

Background: Somatic comorbid symptoms might identify irritable bowel syndrome patients with different aetiologies and needs of treatment. Aims: To measure comorbid symptoms in patients with irritable bowel syndrome in general practice, and to explore characteristics of patients with low, intermediate and high somatic comorbidity. Methods: Prospective study of 208 of 278 consecutive patients with irritable bowel syndrome (Rome 11) in nine general practices. Questionnaires assessed 22 comorbid symptoms (subjective health complaint inventory), psychosocial factors including psychological distress (Symptom Check list-10) and quality of life (Short form-12). Subjective health complaint data from 1240 adults (controls) constituted a reference material. Patients with low, intermediate and high somatic comorbidity were identified by a somatic comorbidity score (17 subjective health complaint items). Health care seeking was assessed after 6-9 months. Results: Patients with irritable bowel syndrome (67% females, mean age 50, s.d. 16) reported 20 of 22 comorbid symptoms significantly more frequent than controls (odds ratios = 2-7, P < 0.001). The somatic comorbidity score correlated with psychological distress (R = 0.46, P < 0.001). Patients with high somatic comorbidity reported higher levels of mood disorder, health anxiety, neuroticism, adverse life events and reduced quality of life and increased health care seeking when compared to those with low and intermediate somatic comorbidity (P-values < 0.05). Conclusions: Our findings support the hypothesis that structured assessment of comorbid somatic symptoms might identify subgroups with different aetiology and needs of treatment.