Association of fibromyalgia with cancerous and non-cancerous gastrointestinal comorbidities: a cross-sectional study

Objective Several studies have shown a higher prevalence of irritable bowel syndrome (IBS) among patients with fibromyalgia yet, data regarding association between fibromyalgia and other gastrointestinal disorders have been relatively overlooked. Our aim was to investigate the association between fibromyalgia and gastrointestinal disorders including both benign and malignant conditions. Methods We conducted a retrospective cross-sectional study based on the comprehensive electronic database of the largest health maintenance organisation in Israel. All subjects with a diagnosis of fibromyalgia in their medical records and age- and sex-matched controls were included in the study. We investigated the association of fibromyalgia with benign gastrointestinal disorders including IBS, gastroesophageal reflux disease (GERD), peptic ulcer disease (PUD), coeliac disease, Crohn's disease, ulcerative colitis, and with gastrointestinal malignancies including colorectal, pancreatic, stomach, liver, and bile duct cancers. Results The study enrolled 18, 598 patients with fibromyalgia and 36, 985 controls. The mean age was 56.5 years (standard deviation=14) with a female predominance (91%). Fibromyalgia was significantly associated with IBS (OR 4.61, 95% CI 4.09-5.2, p<0.001), GERD (OR 2.62, 95% CI 2.5-2.75, p<0.001), PUD (OR 2.13, 95% CI 1.98-2.3, p<0.001), coeliac disease (OR 2.08, 95% CI 1.63-2.65, p<0.001), Crohn's disease (OR 1.85, 95% CI 1.408-2.32, p<0.001) and ulcerative colitis (OR 1.81, 95%CI 1.4-2.33, p<0.001). Nonetheless, no significant differences were found regarding the prevalence of gastrointestinal malignancies between the fibromyalgia patients and controls. Conclusion Our findings suggest that FM is positively associated with various benign but not malignant GI disorders.