The correlations between IBS symptoms using IBS-SQ questionnaire and the different enteroendocine cells were as follows: before FMT, pain correlated with the cell densities of each of CgA (r = 0.87, P = 0.02), serotonin (r = 0.87, P = 0.02) and CCK (r = 0.92, P = 0.01) and anorexia correlated with GIP (r = 0.91, P = 0.01) in the PI-IBS subgroup. This evidence concerns the gene GIP and irritable bowel syndrome.