Why do I need to get an EKG and a chest X-ray before I have a colonoscopy?

Not Normally Needed. These tests EKG and Chest Xray is not usually required before Colonoscopy and you should ask your Doctor the reason for it being required You are not given General Anesthsia and these tests are unnecessary for Colonoscopy.
Ask ordering dr. Preoperative testing (e.g., chest radiography, electrocardiography, often performed before surgical procedures.Can be helpful to stratify risk, direct anesthetic choices, and guide postoperative management, but often obtained because of protocol rather than medical necessity. Decision to order preoperative tests should be guided by patient's clinical history, comorbidities and physical exam.
Not sure. That is typically not part of the pre op evaluation unless they are concerned about something specific.
Might not. Routinely, I do not get EKG or chest xray pre colonoscopy unless the patient is over 40 and has not had regular medical care. This is usually a preference of the endoscopist, anesthesiologist or facilty requirements.