In a subgroup analysis, caffeine showed both protective and harmful associations as follows:

Age: a 352% higher IBD risk in adolescents (based on just 1 study)
Location: a 68% higher risk of ulcerative colitis in Americans and a 46% lower risk in Asians
Beverage type: a 57% lower risk of ulcerative colitis from coffee and a 46% lower risk from tea, though other sources (mostly soft drinks) showed a 68% higher risk
Smoking status: an 80% higher risk of Crohn's disease in smokers (based on just 1 study)

Can caffeine protect against inflammatory bowel disease? Original paper