What to Expect During a Colonoscopy
A step-by-step guide to what happens from the moment you arrive until you go home. Know exactly what to expect so you feel prepared and confident.
Overview: Day of Procedure
Plan for approximately 2-3 hours total at the facility, though the colonoscopy itself only takes 20-60 minutes. Here's how your time breaks down:
- Check-in & prep: 30-45 minutes
- The procedure: 20-60 minutes
- Recovery: 30-60 minutes
You'll need someone to drive you home — you cannot drive yourself due to the sedation.
Step-by-Step: What Happens
Arrival & Check-In
Arrive at the endoscopy center or hospital at your scheduled time (usually 30-60 minutes before the procedure). Bring your ID, insurance card, and list of medications. You'll complete paperwork and confirm your health history.
Pre-Procedure Preparation
You'll change into a hospital gown and remove jewelry. A nurse will review your medications, ask about your prep completion, and check your vital signs (blood pressure, heart rate, oxygen level).
IV Placement
A nurse will insert an intravenous (IV) line, usually in your arm or hand. This is used to give you sedation medication and fluids. It feels like a small pinch.
Meet Your Team
You'll meet the gastroenterologist (the doctor performing the procedure), the anesthesiologist or nurse anesthetist (managing your sedation), and the nursing staff. This is a good time to ask any last questions.
Sedation
You'll be wheeled into the procedure room and positioned on your left side. The anesthesia team will give you medication through your IV. Most facilities use moderate sedation (you're drowsy but can respond) or deep sedation (you're essentially asleep). The medication works within seconds — many patients don't remember anything after this point.
The Examination
The doctor gently inserts the colonoscope through your rectum and advances it through your entire colon. Air or CO2 is used to inflate the colon for better visibility. The doctor examines the lining on the way in and out, looking for polyps, inflammation, or other abnormalities. If polyps are found, they're typically removed during the same procedure using special tools passed through the scope.
Recovery
You'll be wheeled to a recovery area where nurses monitor you as the sedation wears off. This takes about 30-60 minutes. You may feel groggy, and you'll likely pass gas — this is normal and encouraged to relieve bloating from the air used during the procedure.
Results Discussion
Before you leave, the doctor will share preliminary findings with you and your companion. You may receive a written summary. If biopsies or polyp samples were taken, final results typically take 1-2 weeks.
Going Home
Your companion will drive you home. Plan to rest for the remainder of the day. You can resume eating — start with light, easy-to-digest foods. Avoid driving, operating machinery, or making important decisions for 24 hours.
About Sedation
There are several sedation options for colonoscopy. Your facility will discuss which is best for you:
Moderate Sedation (Conscious Sedation)
Most common approach. You receive medications like midazolam (Versed) and fentanyl through your IV. You're drowsy and relaxed but can still respond to verbal commands. Many patients have little to no memory of the procedure. Recovery is typically faster.
Deep Sedation (Propofol)
Propofol puts you into a deeper sleep state. You're unconscious and won't remember anything. An anesthesiologist or nurse anesthetist administers and monitors this type of sedation. Recovery may take slightly longer.
Unsedated Colonoscopy
Some patients choose to have the procedure without sedation. This is uncommon in the US but is an option for patients who want to drive themselves home or avoid sedation risks. There may be more discomfort.
💡 What Does Sedation Feel Like?
Most patients describe the sedation as feeling very relaxed and sleepy, similar to the feeling just before falling asleep. Many say "the last thing I remember is the medication going in, then I woke up in recovery." Some patients have hazy memories of the procedure but report no pain.
What the Doctor is Looking For
- Polyps — small growths on the colon lining that can potentially develop into cancer
- Adenomas — a type of polyp with higher cancer risk; most are removed during the procedure
- Colorectal cancer — suspicious masses or lesions that require biopsy
- Inflammation — signs of inflammatory bowel disease (Crohn's or ulcerative colitis)
- Diverticula — small pouches in the colon wall (common and usually harmless)
- Hemorrhoids — swollen blood vessels near the rectum
- Bleeding sources — identifying causes of rectal bleeding or anemia
After the Procedure
The First Few Hours
- Rest at home — the sedation effects can last several hours
- Pass gas — this relieves bloating; don't be embarrassed, it's expected
- Start with light foods — crackers, soup, toast; avoid heavy or spicy meals
- Drink plenty of fluids — you've been fasting and may be dehydrated
- No driving for 24 hours — sedation impairs judgment even when you feel fine
The Next Day
- Most people can return to normal activities, including work
- Resume your regular diet unless instructed otherwise
- Resume medications as directed by your doctor
- Minor cramping or bloating may persist — this is normal
If Polyps Were Removed
- Avoid aspirin, ibuprofen, and blood thinners for several days (as directed)
- Avoid strenuous exercise and heavy lifting for 3-5 days
- Minor bleeding (streaks on toilet paper) is normal; heavy bleeding is not
- Pathology results usually take 1-2 weeks
When to Call Your Doctor
Contact your doctor immediately or go to the emergency room if you experience:
- Heavy bleeding — more than a tablespoon of blood or clots
- Severe abdominal pain — intense, worsening, or constant pain
- Fever — temperature over 101°F (38.3°C)
- Unable to pass gas or have bowel movement for more than 24 hours
- Signs of infection — chills, increasing pain, or feeling very unwell
These symptoms could indicate complications like bleeding or perforation, which are rare but require prompt medical attention.