A blood test may be able to predict Crohn's disease years before symptoms appear. The test is reported to be able to detect the disease, although the exact timeframe is unclear, with one report suggesting it could be up to 10 years before symptoms appear. However, there is also mention of a stool test and dietary clues being related to inflammatory bowel disease, and one unrelated report mentions a blood test predicting dementia, causing some confusion about the specifics of the Crohn's disease prediction.