The densities of CgA cells in the total colon (mean ± SEM) among the controls and the IBS patients before and after receiving dietary guidance were 83.3 ± 10.1, 38.6 ± 3.7, and 64.7 ± 4.2 cells/mm2, respectively (P = 0.0004), and were unchanged in the rectum. This evidence concerns the gene CGA and irritable bowel syndrome.