Comparative characteristics of fatigue in irritable bowel syndrome and inflammatory bowel disease: A systematic review and meta-analysis

Objective: Fatigue is a common symptom in both irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). This study aimed to distinguish fatigue characteristics in IBS and IBD, two functional and organic disorders. Methods: We systematically searched the PubMed and Cochrane Library databases from inception to June 30, 2023, and conducted a meta-analysis to generate precise estimates and 95% confidence intervals. The analyses were stratified by fatigue type, severity, sex, disease phase, and comorbidities, and study quality was assessed using Newcastle-Ottawa Scale (NOS). Results: Our analysis included 74 data (13 IBS, 31 CD, 30 UC) encompassing 16,689 participants (6484 males, 7402 females, and 2803 unknown). Overall, fatigue prevalence trended higher in IBS (54.5% [95%CI, 44.5-64.6]), followed by CD (49.8% [95%CI, 44.0-55.5]) and UC (43.6% [95%CI, 38.5-48.7]). This pattern persisted across sub-analyses, including general fatigue (63.4% vs. 51.3% vs. 45.3%) and moderate to severe fatigue (73.8% vs. 59.5% vs. 52.7%) for IBS, CD, and UC, respectively. Female predominance was observed in all three diseases (odds ratio: 1.5 in IBS and CD, 1.8 in UC). Fatigue prevalence significantly varied between disease phases (active vs. remission) in CD (61.3% vs. 36.3%) and UC (53.8% vs. 32.6%). Anemia, anxiety/depression, and/or IBS-like symptoms also contributed to fatigue in CD and UC. Conclusions: This study is the first extensive comparison of fatigue prevalence and features in IBS, CD, and UC. The findings offer valuable insights for treatment and management, aiding our understanding of functional and organic diseases.