A colonoscopy is a common screening procedure used to detect changes or abnormalities in the large intestine (colon) and rectum. During a colonoscopy, a long, flexible tube called a colonoscope is inserted into the rectum and guided through the entire colon. The colonoscope has a camera at the end which allows the doctor to view the lining of the colon on a monitor.
Quick Answers
– A biopsy is not always performed during a colonoscopy, it depends on if the doctor sees any suspicious areas that need further evaluation.
– Biopsies are more commonly performed during a colonoscopy if polyps are found, as doctors will remove polyps for analysis.
– Even if no abnormalities are seen, some doctors will take random tissue samples (biopsies) to screen for microscopic changes.
– Taking biopsies does increase procedure time and involves removing small pieces of tissue from the colon lining for examination under a microscope.
– Biopsy results can identify benign or precancerous polyps, inflammation, infections, or sometimes cancer.
When are biopsies performed during colonoscopies?
While biopsies are not performed during every colonoscopy procedure, there are several situations where a doctor may collect tissue samples from the colon or rectum for further analysis:
- If polyps are found – Polyps are abnormal growths that can sometimes turn cancerous over time. The doctor will usually remove any polyps encountered during the colonoscopy for biopsy.
- Areas of irritation, lesions, ulcers or other abnormalities – If the doctor sees any unusual lesions, growths, ulcers or other suspicious areas, they may collect samples from these sites.
- Random biopsies – Some doctors perform random biopsies even when the colon appears normal. This is to screen for microscopic changes that can’t be seen by eye.
- If you have inflammatory bowel disease – Regular biopsies may be recommended to monitor conditions like Crohn’s disease or ulcerative colitis.
- Previous cancer or polyps – If you have a history of colorectal cancer or certain types of polyps, your doctor may collect routine biopsies to monitor for recurrence.
So in summary, biopsies are more commonly performed if abnormalities are found during the colonoscopy. However, they may also be done at a doctor’s discretion even if nothing unusual is seen initially.
Why are biopsies important?
Biopsies collected during a colonoscopy play an important diagnostic role. Microscopic examination of the tissue can reveal changes that aren’t visible during the actual procedure. Reasons a doctor might recommend a biopsy include:
- Identifying polyps – The tissue sample will determine if a polyp is benign (non-cancerous) or precancerous and requires removal.
- Detecting cancer – Biopsies can occasionally detect cancerous lesions in the colon lining.
- Tracking cancer – If you have a history of colon cancer, regular biopsies monitor for recurrence.
- Monitoring diseases – Biopsies help track the extent and severity of diseases like inflammatory bowel disease.
- Identifying infections – Certain infections can affect the gastrointestinal tract and may be identified on biopsy.
- Assessing inflammation – Biopsies look for signs of inflammation that may explain symptoms like diarrhea or abdominal pain.
Without biopsies, some polyps and early cancers could be missed. Biopsy analysis also provides critical information about the nature of any abnormalities found.
How are biopsies performed?
During a colonoscopy, tissue samples for biopsy can be collected in two main ways:
- Forceps biopsies – Small forceps are passed through the colonoscope to pinch off tiny samples of tissue from the colon lining. Several samples may be taken from abnormal looking areas.
- Polyp removal – If polyps are found, they will be removed (polypectomy) for biopsy analysis. A wire loop or snare is used to excise the entire polyp.
Both methods are done through the colonoscope instrument without making any external incisions. Patients are given sedation medication intravenously to keep comfortable during biopsies. You should not feel any pain as the biopsies are performed.
Forceps biopsies
Forceps biopsies involve taking tiny tissue samples about 2-3 mm in size from the surface of the colon lining. The doctor guides the colonoscope to target areas they want to investigate more closely. Then biopsy forceps are passed through the scope to pinch off and collect the specimen.
This only removes a superficial sample of tissue. Forceps biopsies are frequently taken in multiples, from 6-12 different areas of the colon. If any polyps are seen, forceps biopsies may be done on these lesions as well as on normal looking tissue.
Polypectomy
All polyps encountered during a colonoscopy are removed by excising them off the lining of the colon. Most are removed with a wire loop or snare that is threaded through the colonoscope and used to encircle the polyp’s base and sever it.
The entire polyp is then collected and sent to pathology to determine if it is benign or precancerous tissue that requires ongoing surveillance.
Preparing for biopsies
No specific preparation is needed for undergoing biopsies during a routine colonoscopy. The same bowel prep is used to clean out the colon beforehand. However there are a few things to keep in mind:
- Let your doctor know if you take any blood thinning medications, as these may need to be stopped temporarily before polyp removal or biopsies.
- Follow your doctor’s instructions for fasting and diet restrictions the day before your procedure.
- You will be given sedation through an IV line before biopsies are taken to minimize any potential discomfort.
- Arrange for someone to drive you home after your colonoscopy, as you will be groggy from the sedation medications.
- Understand there are small risks of heavy bleeding or infection from biopsy sites that your doctor will discuss.
Inform your doctor if you have any concerns about undergoing biopsies or question why they are recommended in your individual case.
What to expect during the biopsies
You will be given IV sedation before any biopsies are performed, so you should not feel any pain. Here’s what to expect if your doctor takes biopsies:
- The colonoscope will be guided to any areas of interest and remain in place briefly.
- You may feel some pressure or pushing sensations internally as the forceps pinch tissue samples.
- If polyps are removed, you may feel some cramping as a wire loop encircles the polyp.
- Biopsies only take a few seconds each and adding several biopsies usually only prolongs the procedure by 5-10 minutes.
- Tissue samples are so small there is minimal bleeding and you likely won’t feel anything after the colonoscopy.
- If a large polyp is removed, you may feel some abdominal soreness similar to gas pain.
Keep in mind you will be lying on your side and sedated during the entire colonoscopy. Any sensations from biopsies will be brief. Let your doctor know if you experience significant pain or discomfort during the procedure.
Recovering from biopsies
You can expect a normal recovery after having biopsies taken during a colonoscopy. Here are some tips for after your procedure:
- Rest at home for the remainder of the day after your colonoscopy due to the sedation effects.
- Resume eating normally unless otherwise instructed. Drink plenty of fluids.
- Avoid driving, operating machinery or making important decisions for 24 hours after sedation.
- Take over-the-counter pain relievers as needed for soreness or abdominal discomfort.
- Watch for signs of bleeding such as rectal bleeding, dizziness or fatigue.
- Call your doctor if you have a fever over 101°F which could indicate an infection.
Serious complications from biopsies are uncommon. But call your doctor if pain or bleeding seem excessive. Most people feel ready to return to normal activities within a day after the procedure.
Biopsy results
It takes approximately 1-2 weeks to receive biopsy results after a colonoscopy. A pathologist will analyze the samples under a microscope and issue a pathology report. If polyps were removed, the report will indicate:
- Type of polyp (hyperplastic, adenomatous, inflammatory, etc)
- Dysplasia level if adenomatous – this indicates risk of developing into cancer
- Cancer status if malignant cells are identified
- Involvement of margins if a polyp was partially removed
Your doctor will explain the biopsy results and recommended follow up. For example, precancerous adenomatous polyps will require ongoing colonoscopy surveillance. Hyperplastic polyps may just need repeat screening at 10 year intervals.
Biopsies that only sample normal colon tissue often come back as “negative” or “benign.” Your doctor will likely communicate significant biopsy results by phone or patient portal within a few days. Follow up promptly if you don’t receive biopsy results within 2 weeks after your procedure.
Are there risks or complications?
Biopsies performed during colonoscopy are very safe procedures overall. However, as with any invasive test, there are some possible risks and complications to consider:
- Bleeding – Bleeding can occur if a biopsy is taken too deeply. However it is usually minimal.
- Infection – A slight infection risk exists if bacteria are introduced into the biopsy site.
- Perforation – The colon wall can potentially be perforated if a forceps biopsy sample is taken too deeply. However this is extremely rare.
- Reactions to sedation – Some people may have nausea, vomiting or reactions to sedation medications used.
Make sure to contact your doctor if you have excessive bleeding, fevers/chills, severe abdominal pain or other concerning symptoms after your colonoscopy. Prompt antibiotic treatment may be needed if an infection develops.
How much does biopsy increase procedure time?
Taking biopsies only minimally prolongs the length of a routine colonoscopy. Here is how biopsies impact the time involved:
- A typical screening colonoscopy without biopsies usually takes 15-30 minutes.
- If forceps biopsies are performed, it generally adds 5-10 minutes to the procedure length.
- Removing large or multiple polyps for biopsy may extend the colonoscopy by up to 30 minutes.
- So expect your total procedure time to last anywhere from 20 minutes up to an hour if biopsies are involved.
The time required also depends on factors like efficacy of the bowel prep, how carefully the doctor examines the colon tissue, and any difficulties navigating flexures or folds in the colon.
Talk to your doctor prior to your colonoscopy to get a better estimate of how long your particular procedure will take if biopsies are anticipated. You can plan accordingly for accompanying sedation effects and recovery time.
Can you request no biopsy be done?
Patients do have the right to decline biopsies if they prefer. However, this is not generally recommended since biopsy results provide important diagnostic information. Reasons you may want to decline biopsy include:
- Concern over risks like bleeding or perforation
- Worry about pain or complications from the procedure
- Added time and sedation required when biopsy performed
- Cost – biopsies may add to the fees from the colonoscopy procedure
Keep in mind declining biopsy also means missed opportunities to detect cancer or precancerous polyps early. But the decision comes down to an individual choice about the benefits vs potential risks or downsides.
If your doctor recommends a biopsy and you are hesitant, have an open discussion covering:
- Why they advise a biopsy and expected results
- Any alternatives to biopsy to obtain similar information
- Possible risks involved and the likelihood of complications
- Impact on recommendations if biopsy results cannot be obtained
Being well-informed will enable you to make the decision that is right for your health history and personal preferences.
Takeaways
- Biopsies are not performed during all colonoscopies – only when abnormalities are seen or for screening of high-risk patients.
- Reasons for biopsies include polyp removal, suspicious lesions, random sampling or monitoring certain conditions.
- Biopsy methods involve taking samples with forceps or removing polyps using a wire loop.
- Minimal preparation is needed, but inform your doctor of any bleeding risks or sedation concerns.
- Biopsies only cause brief mild discomfort and add 5-10 minutes to the procedure.
- Results take 1-2 weeks and identify any cancer, precancerous tissue or other conditions.
- Discuss the pros and cons if your doctor suggests biopsy and you have hesitations.
The bottom line
During a colonoscopy, biopsies are not performed on every patient. But they may be recommended if polyps, lesions or other abnormal tissue are identified that require closer analysis. Biopsies involve a low risk procedure to collect tiny tissue samples for examination under a microscope. This allows detection of precancerous changes that can allow treatment before progression to colon cancer. While there are some possible complications, the overall benefits of obtaining biopsy results generally outweighs any small risks involved.