Antibodies to Saccharomyces cerevisiae are found in approximately 75% patients with Crohns disease, 15% patients with Ulcerative colitis and 5% of healthy population. This assay helps in distinguishing between Ulcerative colitis & Crohns disease in patients suspected of Inflammatory bowel disease. The presence of antineutrophil cytoplasmic antibodies (ANCA) in the absence of IgA and IgG anti-Saccharomyces cerevisiae antibodies (ASCA) is consistent with the diagnosis of ulcerative colitis; the presence of IgA and IgG ASCA in the absence of ANCA is consistent with Crohn disease.