A method for aiding in the prognosis of Crohn's disease in an individual diagnosed with CD, said method comprising: (a) analyzing a sample obtained from said individual to determine the presence, level or genotype of a combination of serological markers and genetic markers, wherein said serological markers comprise 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-CBir-1 antibody, an anti-I2 antibody, and a perinuclear anti-neutrophil cytoplasmic antibody (pANCA), and wherein said genetic markers comprise SNP8 (R702W), SNP12 (G908R), and SNP13 (3020InsC) in the NOD2 gene; (b) applying a quartile analysis to said serological markers to obtain a quartile sum score for said individual by converting the level of the serological markers ASCA-IgA, ASCA-IgG, anti-OmpC, an anti-CBir-1 antibody, and an anti-I2 antibody into a quartile score, converting the status of the serological marker pANCA into an inverted quartile score, wherein a positive status of this marker is converted into a "1" and a negative status of this marker is converted into a "4", and summing said quartile score for each of said serological markers; and (c) aiding in the prognosis of CD by determining a risk for said individual of developing a CD complication over time, said CD complication selected from the group consisting of internal stricturing disease, internal penetrating disease, and a combination thereof, wherein said risk is determined by comparing said QSS and the genotype of said genetic markers for said individual to a sero-genetic model that provides a cumulative probability of developing a CD complication over time, wherein said sero-genetic model is derived by applying logistic regression analysis to the quartile sum scores obtained from the presence or level of said serological markers and the genotype of said genetic markers determined in a retrospective cohort with known outcomes of CD. (a) analyzing a sample obtained from said individual to determine the presence, level or genotype of a combination of serological markers and genetic markers, wherein said serological markers comprise 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-CBir-1 antibody, an anti-I2 antibody, and a perinuclear anti-neutrophil cytoplasmic antibody (pANCA), and wherein said genetic markers comprise SNP8 (R702W), SNP12 (G908R), and SNP13 (3020InsC) in the NOD2 gene; (b) applying a quartile analysis to said serological markers to obtain a quartile sum score for said individual by converting the level of the serological markers ASCA-IgA, ASCA-IgG, anti-OmpC, an anti-CBir-1 antibody, and an anti-I2 antibody into a quartile score, converting the status of the serological marker pANCA into an inverted quartile score, wherein a positive status of this marker is converted into a "1" and a negative status of this marker is converted into a "4", and summing said quartile score for each of said serological markers; and converting the level of the serological markers ASCA-IgA, ASCA-IgG, anti-OmpC, an anti-CBir-1 antibody, and an anti-I2 antibody into a quartile score, converting the status of the serological marker pANCA into an inverted quartile score, wherein a positive status of this marker is converted into a "1" and a negative status of this marker is converted into a "4", and summing said quartile score for each of said serological markers; and (c) aiding in the prognosis of CD by determining a risk for said individual of developing a CD complication over time, said CD complication selected from the group consisting of internal stricturing disease, internal penetrating disease, and a combination thereof, wherein said risk is determined by comparing said QSS and the genotype of said genetic markers for said individual to a sero-genetic model that provides a cumulative probability of developing a CD complication over time, wherein said sero-genetic model is derived by applying logistic regression analysis to the quartile sum scores obtained from the presence or level of said serological markers and the genotype of said genetic markers determined in a retrospective cohort with known outcomes of CD.