After multivariate regression, including all significant risk factors in univariate analysis, only abnormal CRP values (OR 5.1, 95% CI 1.3–20.2), severe anxiety (OR 3.7 95% CI 0.93–15) and sarcopenia (OR 4.4, 95% CI 1.1–20.1) were identified as risk factors for severe fatigue in IBD patients. The gene discussed is CRP; the disease is sarcopenia.