Colonic 5Ht2ar gene expression was higher and colonic Sert gene expression was lower in the IBS group compared with the Control group (P < 0.01 and P < 0.05, respectively, Figure 3B), whereas TXYF treatment up-regulated Sert gene expression and down-regulated 5Ht2ar gene expression compared with the IBS group (P < 0.01 and P < 0.05, respectively, Figure 3B). Here, SLC6A4 is linked to irritable bowel syndrome.