<prompt> Best screening test for Crohns disease is:A.S.C.A.P-ANCAFecal alpha 1 anti -trypsinFecal calprotectin  <response>: ASCA-positive anti-saccharomyces cerevisae antibody seen with 70 of CD and 15 of UC patients. p-ANCA positivity is found in about 60-70 of UC patients and 5-10 of CD patients Fecal calprotectin levels correlate well with histologic inflammation, predict relapses, and detect pouchitis 