For the prior-to-catheter group , one week before the removal of catheter , acupoints on the abdomen and back such as Guanyuan ( CV 4 ) , Zhongji ( CV 3 ) , Baliao ( Shangliao ( BL 31 ) , Ciliao ( BL 32 ) , Zhongliao ( BL 33 ) , Xialiao ( BL 34 ) , Jiaji ( EX-B 2 ) and acupoints at distal end such as Zusanli ( ST 36 ) and Sanyinjiao ( SP 6 ) were selected ; after the catheter removal , simple method .