Stool samples help to diagnose certain conditions affecting the digestive tract. These conditions can include infections caused by parasites, viruses or bacteria, or autoimmunity, allergy, and cancer. Secretory immunoglobulin A (secretory IgA, sIgA) is released by mucosal tissue and represents the first line of defense of the GI mucosa and is central to the normal function of the GI tract as an immune barrier. Elevated levels of fecal secretory IgA are associated with an upregulated immune response. Biovendor presents CE IVD Immunoglobulin A (Secretory) in Stool Human ELISA kit for measurement in stool and saliva.