Diagnostic Tests and Procedures Practice Test 2026 - Free Diagnostic Practice Questions and Study Guide

Visual examination of the rectum and sigmoid colon is called proctosigmoidoscopy. This procedure combines proctoscopy (examining the rectum) with sigmoidoscopy (examining the sigmoid colon) using an endoscope inserted through the anus to view the mucosa of these regions, typically reaching into the sigmoid colon. It allows direct visualization, and often the opportunity to take biopsies or perform minor interventions if needed. It’s different from the other options, which are unrelated tests: a newborn metabolic screen (PKU test), a platelet count, and a potassium level test.