A pertinent study indicated that the Atractylodes Macrocephala-Paeonia lactiflora (A-P CHM) pair surpassed Atractylodes Macrocephala or Paeonia lactiflora alone in the treatment of IBS by more effectively reducing the levels of 5-hydroxytryptamine, vasoactive intestinal peptide, and growth inhibitors, stabilizing mast cells, diminishing intestinal hypersensitivity, and enhancing fecal water content in IBS rats [19]. This evidence concerns the gene VIP and irritable bowel syndrome.