Effect of four days of preoperative lactulose on posthaemorrhoidectomy pain: results of placebo controlled trial.

The effect of four days of preoperative lactulose on posthaemorrhoidectomy pain was studied in a prospective double blind randomized trial. All patients received lactulose on admission to hospital, 20 received lactulose for four days before admission, and 22 received placebo. The preoperative lactulose treatment group suffered significantly less pain on defecation for the first four days that they opened their bowels (visual analogue scores in cm: day 1, 4.4 v 5.9; day 2, 4.1 v 6.3; day 3, 4.5 v 6.1; day 4, 4.6 v 6.5), suffered significantly less pain during the first two 24 hour periods after defecation (visual analogue scores in cm: day 1, 5.0 v 7.0; day 2, 3.9 v 6.1), and required significantly less analgesia daily after defecation (0.76 g paracetamol/day v 1.29 g paracetamol/day). These results show that lactulose given for four days preoperatively reduces pain after haemorrhoidectomy.