What is the difference between the sigmoidoscopy, proctosigmoidoscopy, and colonoscopy?What range of CPT codes is used for each?What is the difference between the sigmoidoscopy, proctosigmoidoscopy, and colonoscopy?What range of CPT codes is used for each?What is the difference between the sigmoidoscopy, proctosigmoidoscopy, and colonoscopy?What range of CPT codes is used for each?What is the difference between the sigmoidoscopy, proctosigmoidoscopy, and colonoscopy?What range of CPT codes is used for each?What is the difference between the sigmoidoscopy, proctosigmoidoscopy, and colonoscopy?What range of CPT codes is used for each?What is the difference between the sigmoidoscopy, proctosigmoidoscopy, and colonoscopy?What range of CPT codes is used for each?