A traditional Chinese medicine (TCM) containing simo decoction which contains Fructus aurantii, Radix aucklandiae, Semen arecae and Radix linderae, that can potentially be used to improve gastrointestinal (GI) function following surgery. Upon oral intake of simo decoction, this TCM may stimulate mainly muscarinic M3 receptors, but also muscarinic M2 receptors, calcium channels and nicotinic receptors triggering a release of nitric oxide (NO), while inhibiting adrenergic receptors Altogether, this stimulates the contraction of antral circular smooth muscle, thereby abrogating GI hypomotility and enhancing the return of GI function after surgery.