The answer is 45331, K92.1. CPT® code for a sigmoidoscopy with single or various biopsies is accounted for 45331. This is recorded under Sigmoidoscopy/Biopsy. Symptomatic sigmoidoscopy is constantly packaged with a surgical sigmoidoscopy when both are performed in a similar agent session. The ICD-10-CM code for bleeding stools is found in the Index to Diseases and Injuries under Blood/in/defecation or Hematochezia or Melena and coded K92.1. At the point when a patient comes in with a GI side effect and no conclusive analysis is reported for the indication.