Colonoscopy: Examination of the Large Intestine with a Camera-Equipped Device

What Is a Colonoscopy? What Does Colonoscopy Mean?

A colonoscopy is an endoscopic diagnostic and therapeutic procedure in which the inner surface of the large intestine (colon) and rectum is examined by direct visualization using a flexible device (colonoscope) with a small camera and light source at its tip. This is the short answer to the question "what does colonoscopy mean": the term is a combination of "colon" (large intestine) and "scopy" (viewing, examination), and refers to examining the internal structure of the large intestine through live imaging.

During this procedure, the physician can observe inflammatory changes, polyps, ulcers, bleeding, and masses in the intestinal wall, take biopsies (tissue samples) from areas deemed necessary, and remove some polyps during the procedure. For this reason, colonoscopy is a method used for both diagnostic and therapeutic purposes.

A colonoscopy may be performed by gastroenterology specialists, general surgeons, and physicians experienced in colorectal surgery.

The Difference Between Colonoscopy and Other Bowel Imaging Methods

Methods other than colonoscopy may also be used to evaluate the colon and rectum. Knowing the main differences between these methods helps you better understand the scope of the question "what is a colonoscopy":

• Sigmoidoscopy: Only the last part of the large intestine (the sigmoid colon and rectum) is examined; it provides a shorter and more limited view than colonoscopy.
• CT colonography (virtual colonoscopy): Images of the colon are obtained with computed tomography; however, biopsies cannot be taken and polyps cannot be removed, and if a suspicious finding is detected, a colonoscopy may still be required.
• Fecal occult blood test (FIT/FOBT): A non-invasive screening method; if the result is abnormal, a colonoscopy is recommended to confirm the diagnosis.

Which method is appropriate is determined by the physician based on the patient's age, risk factors, symptoms, and general health status.

What Is a Colonoscopy and How Is It Performed?

In general terms, a colonoscopy is performed as follows:

• The patient is usually positioned on their left side and asked to draw their knees toward the abdomen.
• Sedation or anesthesia may be administered to improve comfort during the procedure.
• The colonoscope is slowly advanced through the anus into the rectum and then into the large intestine.
• To allow a clearer view of the intestinal wall, a small amount of air or carbon dioxide gas is introduced into the bowel through the device.
• The camera images are transmitted to a monitor in the procedure room, and the physician examines the inner surface of the bowel through these images.
• If deemed necessary, biopsies may be taken from abnormal tissue or polyps may be removed.
• When the procedure is complete, the colonoscope is slowly withdrawn.

The areas examined during a colonoscopy may include all segments of the large intestine and the last part of the small intestine (terminal ileum).

Types of Anesthesia Used in Colonoscopy

Different anesthesia approaches may be used to improve comfort during a colonoscopy:

• Conscious sedation (light sedation): The patient is relaxed and may be in a sleep-like state but is not completely unconscious.
• Deep sedation: The patient remains largely asleep throughout the procedure and usually does not remember it.
• General anesthesia: Rarely, it may be preferred depending on the patient's general health status or the complexity of the procedure.

The type of anesthesia to be used is determined according to the patient's age, chronic conditions, previous anesthesia experiences, and the evaluation of the anesthesiologist.

Why Is a Colonoscopy Performed?

A colonoscopy is performed to detect possible abnormalities in the large intestine and rectum and, in some cases, to treat them. Its main indications are as follows:

Colorectal Cancer Screening

In individuals over a certain age (generally 45–50 and older), colonoscopy may be recommended for colorectal cancer screening, taking family history and other risk factors into account. Removing polyps and lesions detected at an early stage may play an important role in preventing the development of colon cancer. Because screening frequency and starting age may vary according to a person's risk profile, you should consult your physician on this matter.

Risk factors for colorectal cancer include advanced age, a family history of colorectal cancer or polyps, chronic inflammatory bowel disease, certain genetic syndromes (for example, Lynch syndrome), a sedentary lifestyle, and smoking. In individuals with risk factors, screening may be started at an earlier age than in the general population; the decision is evaluated by the physician on an individual basis.

Investigation of Symptoms and Complaints

Colonoscopy may be preferred in evaluating the following conditions:

• Long-term or unexplained abdominal pain
• Chronic diarrhea or constipation
• Blood or mucus in the stool, or black stools (melena)
• Unexplained weight loss
• Iron deficiency anemia of unknown cause
• Sudden and persistent change in bowel habits

Detection and Removal of Polyps and Masses

Because polyps detected during a colonoscopy may carry the potential to become cancerous, they are generally removed during the procedure and sent for pathological examination.

Monitoring of Inflammatory Bowel Diseases

Colonoscopy may be used in the diagnosis of chronic bowel diseases such as ulcerative colitis or Crohn's disease and in monitoring disease activity.

Evaluation of Previous Treatment or Surgery

A follow-up colonoscopy may be performed in patients who have previously had polyps removed, undergone surgery, or received cancer treatment.

Preparation Before a Colonoscopy

For a colonoscopy to give reliable results, the contents of the large intestine must be completely cleared. For this reason, a certain preparation process is carried out before the procedure.

Diet Before a Colonoscopy

A few days before the procedure, you switch to a low-fiber, residue-free diet recommended by your physician. On the day before the procedure, a diet of clear liquids only is generally recommended. Examples of these liquids include:

• Broth (clear, free of solids)
• Pulp-free fruit juice (such as apple juice)
• Clear sports drinks
• Strained fruit juice
• Plain coffee or tea (without milk)

During this period, you are asked to avoid solid foods, milk and dairy products, and foods with seeds or skins. Because the duration and details of the diet may vary from person to person, it is important to follow your physician's instructions exactly.

Bowel Cleansing

Bowel cleansing is usually achieved with special cleansing solutions (laxative preparations) taken by mouth. In some cases, an enema may also be included in the preparation. These solutions increase bowel movements and ensure that stool and mucus are completely removed from the intestine.

Nausea may occur during preparation. Drinking the solution slowly, taking short breaks if necessary, and drinking it cold may help reduce this complaint. In case of severe nausea or vomiting, it is recommended that you contact your physician.

The quality of bowel cleansing directly affects the accuracy of the procedure. If cleansing is inadequate, small polyps may be missed or the procedure may need to be repeated. For this reason, it is important to follow the preparation instructions given by your physician completely.

Points to Consider Before a Colonoscopy

• If you take blood-thinning medication, be sure to consult your physician about when to stop these medications before the procedure.
• Inform your physician if you are allergic to any medication or substance.
• You will need to fast for the period specified before the procedure.
• Informing your physician about your chronic conditions (diabetes, cardiovascular diseases, etc.) helps ensure that the preparation process is planned specifically for you.
• Iron supplements may be stopped for a period before the procedure on your physician's recommendation, because these supplements can affect the view of the bowel.
• Patients with diabetes should get information from their physicians on how to adjust their medication and insulin doses during the fasting period.

How Long Does a Colonoscopy Take?

The duration of a colonoscopy varies depending on the length of the area examined, the quality of bowel preparation, and whether polyps are removed or biopsies are taken, but it generally takes between 20 and 45 minutes. The procedure may take longer in complex polyp removals or in cases of challenging anatomy.

How Long Does a Colonoscopy Under Anesthesia Take?

In colonoscopies performed under anesthesia or sedation, the procedure itself still takes approximately 20-45 minutes; however, anesthesia preparation and post-procedure waking/recovery time are added to this. For this reason, the total time spent at the hospital for a colonoscopy under anesthesia can generally range from 1.5 to 3 hours. Ensuring that the patient is fully awake and kept under observation after anesthesia is necessary for a safe discharge.

In patients who receive sedation or general anesthesia, pain and discomfort during the procedure are greatly reduced, and most patients do not remember the procedure. The type of anesthesia (conscious sedation or general anesthesia) is determined based on the patient's general health condition and the anesthesiologist's assessment.

When planning the overall process, arrival at the hospital for preparation, the pre-anesthesia evaluation, the duration of the procedure, and the time spent in the recovery room should all be taken into account together. For this reason, particularly for people traveling from another city or from abroad for the procedure, it is recommended to plan the day of the colonoscopy flexibly, separate from other appointments and travel arrangements.

Biopsy and Polyp Removal During Colonoscopy

Taking biopsies from tissues that appear suspicious during a colonoscopy, or removing polyps when they are detected, is a commonly applied approach. The main reasons for this are as follows:

• Diagnostic confirmation: Microscopic examination of tissue that looks abnormal is necessary for a definitive diagnosis.
• Assessment of cancer risk: Since some polyps may have the potential to turn into cancer over time, pathological examination of the removed tissue is important.
• Staging of the disease: In cases where cancer is detected, the tissue sample contributes to determining the extent of the disease.

During biopsy or polypectomy (polyp removal) procedures, complications such as infection, bleeding, or perforation of the bowel wall may rarely develop. Although the frequency of these risks is low, your physician is expected to inform you about them before the procedure.

Types of Polyps and What the Pathology Result Means

Polyps detected during colonoscopy are generally divided into the following groups:

• Hyperplastic polyps: These are generally low-risk and mostly do not turn into cancer.
• Adenomatous polyps (adenomas): This is a type of polyp that may have the potential to turn into cancer; the frequency of follow-up is determined according to its size and structure.
• Serrated polyps: Some subtypes may be associated with an increased risk of cancer and therefore require careful follow-up.

The pathology result is important both for clarifying the diagnosis and for determining the interval until the next surveillance colonoscopy. The interpretation of results and the follow-up plan must always be made by a physician.

The Process After Colonoscopy

General Care After Colonoscopy

After the procedure, patients are usually kept under observation for a period and are discharged once the effect of anesthesia has worn off. Patients who have received anesthesia or sedation are advised not to drive on the day of the procedure and to have a companion with them.

Gas Pain and Bloating After Colonoscopy

Because of the air or gas introduced into the bowel during the procedure, temporary bloating and gas pain may be felt afterward. This usually resolves on its own within a few hours to a day. To find relief, the following may be used:

• Drinking plenty of fluids
• Light walking
• Anti-gas products with your physician's approval

If the complaints persist or worsen, it is recommended that you consult your physician.

Bleeding After Colonoscopy

After a colonoscopy, a small amount of blood may be seen in the stool, particularly in patients who have had a biopsy or polyp removal; this generally resolves on its own within a short time. However, it is important to seek care at a healthcare facility without delay in the following situations:

• Heavy or continuing bleeding
• Severe abdominal pain
• Fever
• Dizziness or a feeling of fainting
• A hard, tense, or swollen abdomen

Diet After Colonoscopy

After the procedure, light and balanced nutrition is recommended to help the digestive system return to normal:

• Fruits and vegetables: Options that are rich in vitamins and fiber and easy to digest can be preferred.
• Lean protein sources: Sources such as grilled chicken, fish, and legumes.
• Whole grains: Products such as whole-grain bread, oats, and brown rice.
• Foods containing probiotics: Products such as yogurt and kefir may help balance the intestinal flora.
• Drinking plenty of water: This is important for replacing the fluids lost during the preparation process.

It is appropriate to follow the timing your physician recommends for returning to solid and heavy foods. In patients who have undergone polypectomy, avoiding activities such as strenuous exercise, heavy lifting, and air travel for a certain period may be recommended to reduce the risk of bleeding; you should follow the specific instructions given by your physician in this regard.

Evaluating Results After Colonoscopy

Findings observed visually during the procedure can be shared by the physician right away. However, the pathology results of biopsy samples are generally available within a few days to one or two weeks. Based on the results, the physician evaluates whether additional tests are needed, the interval for follow-up colonoscopy, and, if necessary, further treatment options.

Possible Complications of Colonoscopy

Although colonoscopy is generally considered a safe procedure, it may carry certain risks, as with any medical intervention:

• Mild bleeding
• Infection
• Perforation of the bowel wall — rarely seen
• Adverse reactions related to anesthesia
• Temporary abdominal pain or bloating

The frequency of these complications is low; however, your physician must inform you about the possible risks before the procedure and complete the consent process. The risk of complications may vary depending on the patient's age, accompanying chronic conditions, the quality of bowel preparation, and additional interventions performed during the procedure (biopsy, polypectomy, etc.).

Factors Affecting Colonoscopy Prices

Colonoscopy prices may vary depending on many variables, such as the healthcare facility where the procedure is performed, the type of anesthesia used (sedation or general anesthesia), whether a biopsy or polypectomy is performed during the procedure, the physician's experience, the equipment and consumables used, and the need for additional tests depending on the patient's general health condition.

The main factors affecting the price can be summarized as follows:

• Type of anesthesia/sedation: General anesthesia applications generally require more resources than conscious sedation.
• Additional procedures: Taking a biopsy, removing a polyp, or the need for pathological examination may affect the total cost.
• Preliminary evaluation and tests: Pre-procedure evaluations such as blood tests and an ECG may be necessary for some patients.
• Length of hospital stay: The post-anesthesia observation period and any additional observation needed.
• Infrastructure and location of the institution: The technological equipment of the healthcare facility and the city/country in which it is located.

For this reason, rather than giving a fixed price range, the most accurate approach is to obtain up-to-date, personalized information from the healthcare facility where the procedure is planned. For patients planning treatment abroad, since the overall process may also include elements such as preliminary evaluation, the procedure, accommodation, and travel organization, it is recommended to clarify the process as a whole with the healthcare facility.

Since colorectal cancer is among the common types of cancer worldwide, when a physician recommends a colonoscopy, scheduling the procedure without delay is important for early diagnosis.

How Often Should a Colonoscopy Be Performed?

The frequency of colonoscopy is determined by a person's age, family history, findings from previous colonoscopies, and overall risk factors. For example, in individuals who had no polyps detected in a previous examination and have no risk factors, the screening interval may be longer, whereas more frequent follow-up may be recommended for individuals with a history of polyps or a family history of colorectal cancer. You should follow your physician's recommendation for a screening interval tailored to you.

Frequently Asked Questions

Is colonoscopy a painful procedure? Because sedation or anesthesia is administered during the procedure, most patients do not feel pain or do not remember the procedure. Mild discomfort may be felt in colonoscopies performed without anesthesia.

When can I return to normal life after a colonoscopy? Once the effect of the anesthesia has worn off, daily activities can usually be resumed within a day or two. Patients who have received anesthesia are advised not to drive on the day of the procedure.

What happens if a polyp is removed during a colonoscopy? The removed polyp is sent for pathological examination. Based on the results, the physician provides guidance on the follow-up interval and, if necessary, additional treatment.

Who should not undergo a colonoscopy? In patients with certain acute bowel diseases, serious heart or lung conditions, or suspected bowel perforation, the procedure may be postponed or a different method may be preferred. This assessment is made by the physician.

What is the difference between a colonoscopy and a gastroscopy? While gastroscopy examines the upper digestive tract (esophagus, stomach, and duodenum), colonoscopy examines the large intestine and rectum. In some cases, both procedures can be performed in the same session.

When are the results available after a colonoscopy? Visual findings can be evaluated by the physician immediately after the procedure; however, the pathology results of any biopsy samples may generally take anywhere from a few days to one or two weeks.

Which medications should be stopped before a colonoscopy? Medications such as blood thinners, certain iron supplements, and diabetes medications may need to be adjusted before the procedure. The physician's instructions must be followed in this regard; the decision to stop any medication must be made by the physician on an individual basis.

At what age should a colonoscopy be performed? In the general population, colorectal cancer screening can usually begin around the age of 45–50; however, in individuals with a family history or other risk factors, this age may be brought forward. The exact starting age is determined by the physician on an individual basis.