FIELD : medicine. SUBSTANCE : group of inventions relates to medicine and is intended to determine whether an individual with inflammatory bowel disease is susceptible or resistant to anti-SMAD7 therapy. Methods are based on determining the number of CCR9 + FoxP3 + T cells, CCR9 + IFN-gamma + T-cells, CCR9 + IL17A + T-cells, FoxP3 + T-cells, IFN-gamma + T-cells and / or IL17A + T-cells in the sample from the individual. Measurement of T-cell populations is performed by flow cytometry, immunohistochemistry and / or ELISA. Methods for treatment, selection and monitoring of therapy are also described, including the determination of sensitivity to anti-SMAD7. EFFECT : group of inventions improves the effectiveness of treatment due to the rational choice of therapy. 81 cl, 7 tbl, 9 dwg, 4 ex