Inflammation markers such as C-reactive protein (CRP) and Erythrocyte Sedimentation Rate (ESR)
Liver function tests to screen for liver and bile duct problems, which are occasionally seen in some people with Crohn’s disease or ulcerative colitis. Some medications used to treat IBD may be associated with liver test abnormalities and thus need to be monitored on a regular basis.
Electrolyte panel to measure the levels of certain minerals (e.g., potassium), which can drop with IBD-associated diarrhea
Vitamin B-12, which may be low if the small intestine isn't properly absorbing nutrients due to Crohn's disease.