1. A method for classifying whether a sample from an individual is associated with inflammatory bowel disease (IBD), said method comprising: (a) analyzing a sample obtained from said individual to determine the presence or level of at least each of the following markers in said sample: an anti-neutrophil cytoplasmic antibody (ANCA), anti- Saccharomyces cerevisiae immunoglobulin A (ASCA-IgA), anti- Saccharomyces cerevisiae immunoglobulin G (ASCA-IgG), an anti-outer membrane protein C (anti-OmpC) antibody, an anti-flagellin antibody, a perinuclear anti-neutrophil cytoplasmic antibody (pANCA), and C reactive protein (CRP); and (b) applying a learning statistical classifier system comprising a random forest to the presence or level of each of said markers determined in step (a) to classify said sample as an IBD sample or non-IBD sample.