Fig. 3

Causal relationship between exposure IBD, CD, UC and outcome PD according to MR analyses. Estimated ORs that obtained from an inverse-variance weighted analysis were combined from the four exposure databases for IBD and three exposure databases for CD and UC using fixed-effect meta-analyses. PD, Parkinson’s disease; IBD, inflammatory bowel disease; CD, Crohn’s disease; UC, ulcerative colitis; OR, odds ratio; CI, confidence interval