A study led by Dr. Arno Bourgonje analyzed 2,000 serum samples from 500 US military personnel—including 200 who developed Crohn's disease, 200 who developed ulcerative colitis, and 100 healthy controls—collected up to 10 years before diagnosis.

From the articleWarning signs could predict inflammatory bowel disease a decade before diagnosisAlso in Antibody patterns may predict inflammatory bowel disease years before diagnosis, Immune changes could signal inflammatory bowel disease up to 10 years before diagnosis