consent for colonoscopy


Consent for colonoscopy is a precondition for colonoscopy. Several issues surround the idea of consent for colonoscopy. It is a legal requirement based on the principles of autonomy and self determination. Every person has the right to determine if they want a procedure such as colonoscopy or not.

What is informed consent? 

This is a legal requirement for a physician to disclose relevant information to a patient in a way and manner that allows the patient to understand, evaluate, and authorize a specific surgical or medical intervention.

What should be disclosed during informed consent? 

  • The patient’s medical problems, diagnosis, and test results.
  • Nature of colonoscopy.
  • The reason for the colonoscopy.
  • Benefits of colonoscopy.
  • The risks of colonoscopy.
  • Alternatives to colonoscopy
  • The patient’s prognosis if colonoscopy is declined.

Risks and complications of colonoscopy

Common risks and complications

  • Adverse effects of medications given for sedation. 
  • Redness, pain or bruising at the injection site.
  • Mild abdominal pains and discomfort.
  • Nausea and vomiting.
  • Lightheadedness and dizziness.
  • Headaches.
  • Muscle aches and pains.

Uncommon risks and complications

  • Fewer than 1 in every 1,000 person accidentally get a hole in the colon. This is called perforation. If detected at the time of colonoscopy, it can be repaired without the need for surgery. Surgery may be needed to repair the perforation. A colostomy may be needed.
  • Less than 1 in every 1000 person experience a significant bleeding. This is usually from a site where a polyp is removed. Bleeding can occur up to 2 weeks after the colonoscopy. The bleeding may stop on its own, require blood transfusion or another colonoscopy to stop the bleeding.
  • Inability to see the entire colon. This may be due to inadequate bowel prep, a tortuous colon, a redundant colon or a blockage.
  • Difficulty breathing.
  • Pneumonia from aspiration.
  • Low blood pressure requiring intervention.
  • Abnormal heart rhythm.
  • Heart attack.
  • A polyp or lesion may be missed. Small polyps may be missed 5-10 percent of the time.
  • Sneezing and runny nose. 

Rare risks and complications

  • Anaphylaxis to medications used during the colonoscopy.
  • Infection such as bacteria in the blood stream. An antibiotic can be used to treat the infection.
  • Spleen rupture.
  • Stroke.
  • Death. This is very rare.

Who should obtain the informed consent?

  • The physician performing the colonoscopy.
  • Members of the health care team can help with the process.

Who should sign the consent form 

  • The patient, designated family member or the patient’s healthcare power of attorney.

Consent for colonoscopy in a emergency situation

  • In a life threatening situation, if there is not enough time to obtain consent from the patient or a family member, an informed consent can be forgone.
  • The emergency must be properly documented and other members of the healthcare team should agree with the decision.

Consent for colonoscopy in an incompetent person 

  • Consent can be obtained from a parent, adult child, legal guardian or surrogate.


Consent for colonoscopy is an integral aspect of colonoscopy. Colonoscopy saves lives. Know the risks and benefits. Read factors that determine the outcome of a colonoscopy. 

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