Colonoscopy — What to Expect
A colonoscopy uses a flexible camera to look inside the entire large intestine. Most are done for screening or to investigate symptoms. The procedure itself is short (20–40 minutes) and you sleep through it; the preparation the day before is the harder part.
Results
Verbal preliminary results before you leave the unit. Biopsy and polyp pathology results: 7–14 days. Surveillance recommendations: communicated within 2–3 weeks.
This article is educational and does not replace your doctor's advice. Seek urgent care for any red-flag symptoms.
What is it?
A colonoscopy is an examination of the entire large intestine (colon and rectum) using a colonoscope — a thin, flexible tube about the thickness of a finger, with a high-definition camera and light at the tip. The doctor passes the colonoscope through the anus and gently advances it through the rectum and around the colon, all the way to where the small intestine joins the colon. Air or carbon dioxide is gently puffed in to open the bowel for clear viewing. Small instruments can be passed through the scope to take biopsies, remove polyps, or stop bleeding — all without surgery.
Why is it done?
There are three main reasons:
1. Screening for colon cancer. In adults aged 45 and older without symptoms, colonoscopy can find and remove pre-cancerous polyps before they become cancer. This is the single most effective cancer prevention test we have.
2. Investigating symptoms. Bleeding from the rectum, persistent change in bowel habits, unexplained iron deficiency anemia, or unexplained weight loss all warrant a colonoscopy.
3. Surveillance and treatment. People with prior polyps, IBD, or a strong family history of colon cancer need follow-up colonoscopies. The procedure can also remove polyps, stop bleeding, or treat strictures.
Who needs it?
- All adults aged 45–75 for screening (Saudi MOH guideline)
- People with first-degree relatives who had colon cancer or advanced polyps — start 10 years before the relative's age at diagnosis or at 40, whichever is earlier
- Anyone with persistent diarrhea, constipation, or change in bowel habits over 6 weeks
- Anyone with rectal bleeding (even small amounts)
- Anyone with iron-deficiency anemia and no obvious cause
- People with IBD on a long-term surveillance schedule
Before the procedure
5–7 days before, the day before, and the morning of
- 5–7 days before: Stop iron tablets, fish oil, and any high-fiber supplements. Discuss blood thinners (warfarin, aspirin, DOACs, clopidogrel) with the booking team — some need to be paused.
- 3 days before: Stop nuts, seeds, and high-fiber foods (whole-grain bread, raw vegetables).
- Day before: Clear-liquid diet only — water, clear juice without pulp, broth, qahwa or tea without milk, jelly. Avoid red, purple, or orange liquids.
- Day before evening: Start the bowel prep solution. Drink it as instructed (usually split-dose: half evening, half early morning of the procedure).
- Day of procedure: Continue clear liquids until 2 hours before arrival. Take any approved morning medications with a small sip of water.
- Bring a list of your medications and allergies. Wear loose clothing. Arrange someone to drive you home — you cannot drive after sedation.
During the procedure
When you arrive, you will change into a hospital gown. A nurse will ask about your medical history, take your vital signs, and place a small IV line in your arm.
In the procedure room you will lie on your left side. The team includes the doctor, an endoscopy nurse, and an anesthetist or sedation nurse. Sedation is given through the IV — most patients in Saudi Arabia receive propofol, which puts you in a light sleep. You will not feel or remember the procedure.
The colonoscopy itself takes 20–40 minutes. The doctor advances the colonoscope to the cecum (where the small intestine meets the colon) and then carefully withdraws it, examining every segment of the colon wall. Polyps found are removed and saved for the lab. Any biopsies are taken with tiny forceps.
When the procedure is over, you will be wheeled to a recovery area where you wake up gradually over 30–60 minutes.
After the procedure
You will spend 30–60 minutes in the recovery area while the sedation wears off. You may feel bloated or have mild gas pains for a few hours — this is from the air pumped in during the procedure and resolves on its own.
Once awake, you can eat normally. Most people resume regular activity by the next day. The doctor will give you preliminary verbal results before you leave; biopsy or polyp pathology results take 7–14 days and are usually communicated by phone or through the patient portal.
For 24 hours: do not drive, do not sign legal documents, do not consume alcohol, and do not operate machinery — sedation lingers in the bloodstream even when you feel awake.
Risks
Risks — honest numbers
- Bleeding: 1–2 in 1000 procedures, usually from polyp removal. Most stops on its own or is treated during the procedure.
- Perforation (a hole in the bowel wall): less than 1 in 1000 for diagnostic; 1–2 in 1000 for polyp removal. Almost always managed endoscopically with clips, rarely needs surgery.
- Sedation reaction: rare with modern propofol; the team monitors you continuously.
- Missed lesions: 5–10% of small polyps can be missed even with excellent technique. Quality programs minimize this; that is why a good prep matters.
When you get results
Alternatives if you decline
If you decline a screening colonoscopy, alternatives include FIT (fecal immunochemical test, annually), CT colonography ("virtual colonoscopy," every 5 years), or stool DNA testing. None are as sensitive as colonoscopy and ALL require a colonoscopy if abnormal.
In the Saudi context
Colonoscopy is widely available across Saudi Arabia in MOH hospitals, university hospitals, and private centers. Class A and B insurance plans typically cover screening colonoscopy. Several MOH centers also run free CRC screening campaigns. Sedation is the standard — true "awake" colonoscopy is uncommon. If you have any concerns about sedation safety (e.g. sleep apnea), tell the team at booking.
Questions to ask your doctor
Save this list or print it before your appointment — doctors appreciate prepared patients.
- Do I need to stop my blood thinners or anti-platelet drugs before the procedure?
- Can I take my morning diabetes or blood pressure medication on the day?
- What sedation will be used and is it safe with my medical conditions?
- When will I get the results, and what does each finding mean?
- When should my next colonoscopy be?
Trusted resources
Medically reviewed by: SGA Patient Education Panel · Last reviewed 24/04/2026