1st order laboratory parameters – obligatory laboratory tests.
- Small blood count*
- Differential blood count*
- Inflammatory parameters – C-reactive protein* (CRP) or erythrocyte sedimentation rate* (ESR).
- Urine status (rapid test for: Nitrite, protein, hemoglobin, erythrocytes, leukocytes, urobilinogen) incl. sediment, if necessary urine culture (pathogen detection and resistogram, that is, testing of suitable antibiotics for sensitivity / resistance)* .
- Transglutaminase antibodies* or endomysium antibodies (EMA) and total IgA in serum – as celiac disease screening* ; in case of IgA deficiency: genetic test (DNA analysis)/detection of celiac disease-associated HLA-DQ gene constellation, this allows with very high certainty the exclusion of celiac disease.
- Calprotectin/lactoferrin* (fecal inflammation marker) – for suspected chronic bowel disease or inflammatory bowel disease (Crohn’s disease, ulcerative colitis).
- Stool samples for parasites* (such as Giardia lamblia, Dientamoeba fragilis), bacterial pathogens and worm eggs (microbiology) – in irritable bowel syndrome (IBS) of diarrhea type (diarrhea) or mixed type.
Laboratory parameters 2nd order – depending on the results of the medical history, physical examination, etc. – for differential diagnostic clarification / course of irritable bowel syndrome after elimination diet (targeted food selection).
- Electrolytes – sodium, potassium
- Creatinine*
- Lipase*
- Alanine aminotransferase (ALT; GPT)* , gamma-GT* , bilirubin* .
- Total IgA*
- TSH* (thyroid stimulating hormone) – exclusion of hyperthyroidism (hyperthyroidism).
- Fasting glucose* (fasting blood glucose)/HbA1c – exclusion of diabetes mellitus.
- Allergy testing – IgE, total, allergen-specific IgE (IgG titers to food allergens should not be tested).
- Leukocyte activation test (eg, Alcat tests of the U.S. company Cell Science Systems; test in which the leukocytes (white blood cells) are exposed ex vivo to an extract of 200 different foods; ex vivo: procedure in which the leukocytes, taken from the living organism (here by blood sampling) and cultivated outside it for a limited time) – use of the test as a guide in the elimination diet.
- Microbiome analysis (so-called “whole genome shotgun sequencing”) [in the foreground: Firmicutes].
* Basic laboratory in children
