Background: Fatigue syndromes and irritable bowel syndrome (IBS) often occur together. Explanations include being different manifestations of the same condition and simply sharing some symptoms.
Method: A matched case-control study in UK primary care, using data collected prospectively in the General Practice Research Database (GPRD). The main outcome measures were: health-care utilization, specific symptoms, and diagnoses. Risk markers were divided into distant (from 3 years to 1 year before diagnosis) and recent (1 year before diagnosis).
Results: A total of 4,388 patients with any fatigue syndrome were matched to two groups of patients: those attending for IBS and those attending for another reason.
Infections were specific risk markers for both syndromes, with:
• Viral infections being a risk marker for a fatigue syndrome [odds ratios (ORs) 2.3-6.3], with a higher risk closer to onset, [Note: an OR of 1.0 would indicate no difference in odds. Thus an OR of 2.3, for example, would indicate 130% greater odds of this risk marker vs. the comparison group; and an OR of 6.3 would indicate 530% greater odds.]
• And gastroenteritis a risk for IBS (OR 1.47, compared to a fatigue syndrome).
Chronic fatigue syndrome (CFS) shared more distant risk markers with IBS than other fatigue syndromes, particularly other symptom-based disorders (OR 3.8) and depressive disorders (OR 2.3), but depressive disorders were a greater risk for CFS than IBS (OR 2.4).
Viral infections were more of a recent risk marker for CFS compared to IBS (OR 2.8), with gastroenteritis a greater risk for IBS (OR 2.4).
• Both fatigue and irritable bowel syndromes share predisposing risk markers,
• But triggering risk markers differ.
Fatigue syndromes are heterogeneous, with CFS sharing predisposing risks with IBS, suggesting a common predisposing pathophysiology.
Source: Psychological Medicine, Apr 15, 2009, PMID: 19366500, by Hamilton WT, Gallagher AM, Thomas JM, White PD. Academic Unit of Primary Health Care, University of Bristol, Bristol, UK. [E-mail: firstname.lastname@example.org]