Adverse Events in Colonoscopy: What Patients Need to Know
Information about potential adverse events that may occur during or after a colonoscopy procedure.
{"Adverse events are uncommon complications that may happen during colonoscopy","Bleeding and perforation are the most serious but rare complications","Your healthcare team monitors for these events during and after the procedure"}
Key facts at a glance
- LOINC
- 111913-0
- Short code
- AE_COLON
- Synonyms
- Advrs evnt during proc Colon Endscpy
- Category
- chemistry
- Sample
- serum
- Container
- Not applicable - this is a documentation code, not a specimen-based test
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 18 years
- Method
- endoscopy
- CPT
- 45378
- SNOMED
- 73710001
- Specimen volume
- Not applicable
- Stability
- Not applicable
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
An adverse event in colonoscopy is any unexpected or harmful problem that occurs during or shortly after the procedure, such as bleeding, a tear in the colon wall, or a reaction to sedation. Most of these events are minor and can be treated right away by your care team.
An adverse event during colonoscopy refers to any unexpected complication that occurs during or after the procedure. While colonoscopies are generally very safe, like any medical procedure, there are potential risks that healthcare providers monitor for and document.
Possible adverse events include bleeding at a biopsy or polyp removal site, perforation of the colon, reactions to sedation medications, infection, and abdominal discomfort or bloating. Serious complications are rare, but knowing the warning signs helps you get care quickly if needed.
The most common adverse events include: bleeding (especially if a polyp is removed), perforation (a small tear in the colon wall), and reactions to sedation medications. Less common events may include infection, splenic injury, or post-polypectomy syndrome.
These events are monitored closely throughout the procedure with continuous checks of your heart rate, blood pressure, and oxygen levels, followed by observation in the recovery area. After you go home, you will receive clear instructions on which symptoms to watch for and when to contact your doctor.
Your medical team closely observes you during and after the procedure. Vital signs, physical examination, and any symptoms you report are all part of monitoring for complications. If an adverse event is suspected, appropriate interventions are initiated immediately.
Reference range
Not applicable - this is an adverse event documentation code used to capture and record complications occurring during colonoscopy procedures. Results are documented as present or absent, with severity grading as applicable.N/A
Standard colonoscopy preparation instructions apply for the procedure. Adverse event documentation occurs during and after the procedure. No specific patient preparation required for the adverse event documentation itself.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Documentation of adverse events helps healthcare providers track procedure safety, improve techniques, and inform patients about risks. The overall complication rate for colonoscopy is low (less than 1% for serious complications), making it a very safe and effective screening procedure.
Frequently asked questions
How common are adverse events during colonoscopy?
What symptoms should I watch for after colonoscopy?
Who is at higher risk for complications?
Sources
- 1
- 2
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy