The aim of this study is assessment of efficacy of Cholestyramine, 15% ointment on postsurgical pain of hemorrhoidectomy. Ninety-one (91) patients were randomly enrolled to receive either Cholestramine (n=47) or placebo (n=44). Inclusion criteria were presence of internal hemorrhoids degrees three and four. Exclusion criteria were anal fissure, previous hemorrhoidectomy, drug addiction, pregnancy, presence of cirrhosis, receiving oral nitroglycerin or Cholestyramine. Patients in intervention group received 15% Cholestyramine ointment with almond oil rubbed on the site of rectal wound, immediately and 12 hours after surgery and then 3 grams three times daily for 14 days. In control group almond oil was used as placebo with the same dose and administration route. Pain after surgery and pain after defecation were compared between two groups as outcomes of this study.