Colonoscopy is an examination of the inside of the colon and rectum using a flexible instrument with a camera. It allows the doctor to investigate the cause of symptoms, take samples from suspicious areas and remove suitable polyps, which are tissue growths on the inner lining of the bowel. The examination is not only for people with symptoms; it is also used to detect cancer early in people who have no symptoms.
The aim of preparation is to clean out the bowel. Small changes may be missed if food residue and stool remain. Sometimes the examination has to be repeated. To help prevent this, written instructions on diet, bowel-cleansing medication and fasting are tailored to your appointment time and health.
The difference between investigating symptoms and screening
Screening looks for disease or precancerous changes when there are no symptoms. The American Cancer Society recommends starting screening at age 45 for adults at average risk who have no symptoms. Average risk means there are no particular conditions in the personal or family history requiring earlier, more frequent checks. This age threshold should not be understood as a universal state programme applying to everyone in Azerbaijan; an appropriate screening plan is agreed with the doctor.
As well as colonoscopy, screening options may include stool tests that look for blood invisible to the naked eye, but a positive result usually needs to be investigated with colonoscopy. If a high-quality colonoscopy is normal and the person's risk has not changed, the next screening colonoscopy is often planned for 10 years later. If new symptoms develop, you should not wait until then.
After age 75, the decision to continue is individualised according to general health, previous examinations and the expected benefits and possible risks. A family history of colon cancer, an inherited condition, previous polyps or long-standing bowel inflammation may mean starting earlier and having shorter intervals between examinations. One schedule does not suit everyone.
If you have blood in your stool, unexplained iron deficiency, a persistent change in bowel habits or unexplained weight loss, the purpose is to find the cause of symptoms rather than to screen. In these cases, there is no need to wait until age 45. Whether colonoscopy is appropriate and how urgently it is needed are determined after an initial assessment.
What should the doctor know before preparation?
Your medication list should include vitamins, iron and herbal supplements as well as prescription medicines. Be sure to mention any medication that reduces blood clotting. Do not stop it yourself. The decision depends on why the medicine was prescribed and whether treatment may be needed during the examination.
Diabetes, kidney and heart disease, difficulty with previous bowel preparation, severe constipation and possible pregnancy may affect the choice of preparation. Just as a separate plan is made for insulin and other diabetes medicines on days when you eat less, people with kidney disease need their bowel-cleansing medication chosen by a doctor, rather than on someone else's advice.
If a previous colonoscopy report notes that the bowel was not fully cleaned, the instrument could not examine the entire bowel or there was a problem during sedation, it is useful to show the team that report in advance. Sedation uses medication to reduce anxiety and discomfort.
Diet and bowel cleansing
Dietary restrictions often focus on the day before the examination, although some people are asked to start a low-fibre diet earlier and switch to clear liquids only after a specified time. A low-fibre diet temporarily limits foods such as products containing seeds or bran, raw vegetables and nuts. It differs from usual healthy eating advice because it is a short-term preparation.
Clear liquids include water, strained clear broth, tea without milk and clear juice without pulp. Milk, yoghurt and juice with pulp are not included. You may be advised to avoid red and purple drinks. The clinic's instructions should state separately when you must stop all food and fluids.
Bowel-cleansing medication usually causes watery stools. For morning colonoscopies, a split-dose regimen is often chosen, with part of the preparation taken the evening before and the rest on the morning of the examination. The product, amount and timing can vary, so one patient's prescription should not be assumed to suit another.
During preparation, it is helpful to stay somewhere with easy access to a toilet.
Drink the permitted fluids in the amounts specified in the instructions; if you have heart or kidney disease, the amount is agreed separately.
Contact the endoscopy unit if vomiting or another difficulty prevents you from finishing the preparation.
If you have severe abdominal pain, marked bloating and cannot pass stool, seek urgent medical advice rather than taking more laxatives.
Stools becoming clearer may show that preparation is progressing, but this is not a reason to skip the remaining dose yourself. If the preparation has not worked fully, it is important to tell the team before the examination. They will assess whether to proceed, change the preparation or reschedule.
What happens during the examination and if a polyp is found?
You lie on your side. The colonoscope is inserted through the anus, and air or carbon dioxide is introduced to make the bowel wall easier to see; your position may be changed to improve the view. Sedation and pain relief are discussed beforehand, because although deeper sedation is needed in some cases, the same approach is not used for every colonoscopy or every patient.
Breathing, pulse and other vital signs are monitored during sedation. Even so, a reaction to the medication is possible. Other risks of colonoscopy include bleeding and a hole in the bowel wall; the risk varies with the procedure performed and the person's condition.
A small, suitable polyp is often removed during the same examination. The removed tissue is examined under a microscope. A large or complex growth, or one that may contain cancer, may first need further assessment, referral to a doctor experienced in these procedures and a separate treatment plan. Finding a polyp does not automatically mean abdominal surgery.
Going home and receiving the results
If you have sedation, arrange in advance for an adult to take you home. Restrictions on driving, operating machinery and making important decisions are explained according to the medication used. Feeling alert does not necessarily mean that your reactions have fully recovered.
You may have short-lived bloating and mild cramps. Increasing abdominal pain, fever, persistent or increasing bleeding, dizziness and fainting require urgent medical attention. Bleeding after polyp removal can begin in the following days rather than immediately.
You may receive initial information about what was seen on the day, while the tissue analysis results take longer. Before leaving, it is helpful to be clear about how you will receive the results and who will see you for follow-up. The timing of the next examination is determined by considering bowel cleanliness, whether the examination was complete and the tissue analysis results together.