Bipolar probe coagulation (BICAP) was evaluated and compared with conventional cold biopsy (CBx) as a potential therapeutic modality for eradication of diminutive colonic polyps (DPs). Seventy-seven and 79 DPs were treated with BICAP and CBx, respectively. Twenty-one percent of the BICAP and 29% of the CBx (p greater than 0.05) group had residual polypoid tissue detected at flexible sigmoidoscopy 3 weeks after treatment. Because of incomplete polyp removal, CBx and BICAP coagulation cannot be recommended as definitive therapies for DPs. Neoplasia was present in 22% of DPs located less than 60 cm from the anus, 73% of proximally located small polyps, and 32% of all DPs. Despite apparent eradication at the time of treatment, the incidence of residual polypoid tissue would suggest the need for critical evaluation of other modalities used to eradicate or remove DPs.