A randomized trial comparing direct current therapy and bipolar diathermy in the outpatient treatment of third-degree hemorrhoids. Fifty patients with third-degree hemorrhoids were randomized to receive outpatient treatment with either bipolar diathermy or direct current therapy. Direct current therapy was used to treat 26 patients and bipolar diathermy was used to treat 24 patients. Twenty patients in each group were successfully treated as judged by resolution of symptoms and shrinkage of hemorrhoidal tissue. Both treatments are effective in the outpatient management of large, prolapsing hemorrhoids. Bipolar diathermy is less time consuming and better tolerated. 