What diagnostic tools can help diagnose the cause of diarrhea?

Answer 1

Blood tests - Blood tests can sometimes provide information about the cause of chronic diarrhea and the secondary effects of diarrhea on overall health.

Complete blood count - A complete blood count (CBC) can detect the anemia that results from long-standing blood loss or inflammation. It can also detect an elevated number of white blood cells, which may signal that diarrhea is being caused by inflammation, infections, Allergies, or cancer.

Blood chemistry - Blood chemistry tests can detect dehydration and electrolyte (salt and mineral) imbalances, as well as liver problems and nutritional deficiencies.

Peptides - Certain rare tumors (such as carcinoid or tumors producing "vasoactive intestinal polypeptide") can produce hormones called peptides that promote diarrhea and can be detected in a blood sample.

Antibodies - Tests can detect elevated blood levels of antibodies directed at infectious organisms or antibodies directed at the body's own tissues (called autoantibodies). An example of the latter is an antibody test against tissue transglutaminase. Presence of this autoantibody frequently indicates the presence of celiac disease, a disorder caused by allergy to wheat proteins.

Inflammatory markers - The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels are nonspecific markers of inflammation. Elevation of these markers may signal inflammatory bowel disease (Crohn's disease or ulcerative colitis).