What Are Endoscopy and Colonoscopy? How Are They Performed and When Are They Needed?

What Are Endoscopy and Colonoscopy?

Two of the most important methods used in diagnosing digestive system diseases are endoscopy and colonoscopy. In both procedures, a thin, flexible instrument with a camera at its tip is used to directly visualize the inner surface of the digestive tract. However, the areas examined are different.

When people say “endoscopy,” they usually mean upper gastrointestinal endoscopy, or gastroscopy. Gastroscopy examines the esophagus, the stomach and the first part of the duodenum. Colonoscopy, on the other hand, allows evaluation of the large intestine and, when necessary, the final portion of the small intestine.

One of the important advantages of endoscopic methods is that they are not limited to imaging. During the procedure, biopsies can be taken from the necessary areas, polyps can be removed and some types of bleeding can be treated endoscopically. For this reason, endoscopy and colonoscopy are both diagnostic and, in some cases, therapeutic procedures.

What Is Endoscopy?

Endoscopy is the general term for examining the body’s internal organs with a camera system. When used in the context of the digestive system, it usually refers to gastroscopy or upper gastrointestinal endoscopy.

During gastroscopy, the endoscope is advanced through the mouth to evaluate:

The esophagus,

The stomach,

The duodenum.

Because the inner surface of these areas can be directly visualized, many problems — such as gastritis, ulcers, reflux-related changes and some tumors — can be assessed.

When Is Endoscopy Performed?

Whether endoscopy is necessary is determined by evaluating the patient’s complaints, age, examination findings and risk factors.

Gastroscopy may be needed for prolonged or recurrent stomach pain, difficulty swallowing, unexplained nausea and vomiting, suspected gastrointestinal bleeding and the investigation of certain types of anemia. Reflux complaints that persist despite treatment may also require endoscopic evaluation in some patients.

Detailed evaluation of the patient is particularly important in the presence of alarm symptoms such as unexplained weight loss, difficulty swallowing, signs of bleeding or persistent complaints.

However, this does not mean that endoscopy is required for every case of stomach pain.

How Is Endoscopy Performed?

Gastroscopy is performed by advancing a thin, flexible endoscope through the mouth. Thanks to the camera at the tip of the endoscope, the inner surface of the esophagus, stomach and duodenum is examined in detail on a screen. If a suspicious area is seen during the procedure, a biopsy can be taken.

In many centers, endoscopy can be performed under sedation to increase patient comfort. Sedation is not the same as general anesthesia. Depending on the method used and the patient’s characteristics, medications can be given that reduce the level of consciousness and the discomfort felt during the procedure.

Do You Need to Fast Before Endoscopy?

The stomach must be empty during gastroscopy. For this reason, patients are asked to stop eating and drinking for a certain period before the procedure.

Since the fasting period can vary depending on the patient’s health, the medications they use and the planned sedation method, patients should follow the preparation instructions given to them.

In particular, how diabetes medications, blood thinners and other regularly used medicines should be handled before the procedure should be discussed with the doctor. Medications should not be stopped on the patient’s own initiative.

Why Are Biopsies Taken During Endoscopy?

A biopsy can be taken when tissue seen during endoscopy needs to be examined under the microscope. Taking a biopsy does not necessarily mean cancer is suspected.

Biopsies may be needed for the assessment of gastritis, the investigation of Helicobacter pylori, suspected celiac disease and various other gastrointestinal conditions. In some diseases, a biopsy may be needed for diagnosis even if the surface of the stomach or intestine looks normal on endoscopy.

For this reason, the endoscopy report and the pathology report are two different assessments that complement each other.

What Is Colonoscopy?

Colonoscopy is the endoscopic procedure that allows the large intestine to be examined with a camera system. A thin, flexible instrument called a colonoscope is advanced through the anus and the inner surface of the large intestine is evaluated.

Under suitable conditions, the aim is to examine the entire colon and reach the cecum. When necessary, the terminal ileum — the final portion of the small intestine — can also be evaluated.

One of the most important features of colonoscopy is that it can be used not only to investigate existing diseases but also for colorectal cancer screening and the detection of precancerous polyps.

Why Is Colonoscopy Performed?

Colonoscopy can be performed for various reasons. Blood in the stool, unexplained iron deficiency anemia, a persistent change in bowel habits, prolonged diarrhea or constipation and unexplained abdominal pain may require colonoscopy in some patients.

In addition, risk assessment is important for people with a family history of colon cancer or advanced polyps.

Another important use of colonoscopy is screening for colon and rectal cancer. A significant proportion of colorectal cancers can develop over time from certain polyps. For this reason, detecting and removing polyps before cancer develops is, in suitable patients, one of the most important advantages of colonoscopy.

Is Colonoscopy Only for People with Symptoms?

No. Colonoscopy is not an examination performed only on people with abdominal pain, bleeding or bowel problems. From certain ages onwards, it can also be used for colorectal cancer screening in people with no complaints at all.

The age at which screening begins and the method used can vary according to the person’s risk group. In situations such as a family history of colon cancer, certain hereditary syndromes or inflammatory bowel disease, the screening program may differ from that of the standard-risk group.

For this reason, the screening plan should be determined by evaluating the person’s age and risk factors.

Why Is Preparation Before Colonoscopy So Important?

One of the most important stages of a successful colonoscopy is bowel cleansing. For the inner surface of the large intestine to be evaluated in detail, the stool inside the bowel must be cleared as thoroughly as possible.

Inadequate bowel preparation can cause small polyps or other lesions to be missed. It can also prolong the procedure and, in some cases, make it necessary to repeat the colonoscopy.

For this reason, the quality of a colonoscopy depends not only on the physician performing it but also on the quality of the preparation beforehand.

What Can You Eat Before a Colonoscopy?

The diet before colonoscopy is arranged according to the bowel preparation protocol used.

In the days before the procedure, certain high-fiber foods and foods that can leave residue in the bowel may be restricted. As the procedure approaches, a diet based mainly on clear liquids may be introduced. The solutions prescribed for bowel cleansing must be taken at the specified times.

However, colonoscopy preparation may not be exactly the same for every patient. In particular, elderly patients, those with kidney or heart disease, patients with diabetes and people who take regular medications should follow the specific preparation program given to them.

Is Colonoscopy Painful?

During colonoscopy, the advancement of the scope through the bowel and the controlled introduction of gas into the bowel can cause a feeling of pressure, bloating or cramping.

Since colonoscopy can now frequently be performed under sedation, the discomfort patients feel during the procedure can be reduced considerably.

After the procedure, a short-lived feeling of gas and bloating may occur. Patients who receive sedation must not drive on the same day and should follow the post-procedure instructions given to them.

What Happens If a Polyp Is Found During Colonoscopy?

Colon polyps are growths that develop from the inner surface of the large intestine. Not all polyps are cancer. However, some types of polyps have the potential to turn into cancer over the years.

One of the most important advantages of colonoscopy is that suitable polyps can be removed during the procedure using a technique called polypectomy.

The removed polyp is sent for pathological examination. The pathology result helps determine the type of polyp, its characteristics and the appropriate follow-up interval.

Colonoscopy is therefore an important method not only for detecting colon cancer but also for preventing the development of some cancers.

When Should Colonoscopy Be Repeated After a Polyp Is Removed?

Not every patient in whom a polyp is found needs colonoscopy at the same intervals.

The timing of follow-up is determined by the number of polyps, their size, their pathological features, the quality of the bowel preparation and how thorough the initial colonoscopy was.

In some patients, follow-up at longer intervals is sufficient, while polyps with high-risk features may require earlier re-examination.

For this reason, the question “A polyp was found — how often should I have a colonoscopy?” should not be answered before the pathology result is seen.

Can Endoscopy and Colonoscopy Be Done at the Same Time?

In suitable patients, gastroscopy and colonoscopy can be performed in the same session. Particularly when both the upper and lower gastrointestinal tract need to be evaluated, performing the two procedures under the same sedation can be practical for the patient.

However, performing both procedures together is not necessary for every patient. The decision should be made according to the patient’s complaints and medical needs.

Do Endoscopy and Colonoscopy Carry Risks?

Endoscopy and colonoscopy are widely performed procedures, but as with any medical intervention, they carry certain risks.

In patients who receive sedation, problems related to the medications used can occur. Bleeding can occur after a biopsy or polyp removal. In colonoscopy in particular, perforation of the bowel wall is a rare but important complication.

The risk can vary depending on the type of procedure performed, the size of the polyp removed and the patient’s general health. For this reason, it is important to inform the physician of any medications used and existing conditions before the procedure.

What Should You Watch Out for After Endoscopy and Colonoscopy?

If sedation was used, the patient is kept under observation for a while after the procedure. Mild throat discomfort, gas or bloating may occur.

Most patients can return to their daily lives the same day, but driving after sedation is not allowed.

Medical attention should be sought for unusual symptoms such as severe and worsening abdominal pain, heavy bleeding, high fever or persistent vomiting. Additional patient-specific instructions may be given, particularly after the removal of a large polyp or an advanced endoscopic procedure.

Why Are Endoscopy and Colonoscopy Important for Early Diagnosis?

Some digestive system diseases can progress with mild symptoms for a long time. The important advantage of endoscopy and colonoscopy is that they allow direct evaluation of the inner surface of the digestive tract and, when necessary, tissue sampling during the same procedure.

The ability to detect and remove potentially precancerous polyps during colonoscopy, in particular, makes the method more than just a diagnostic tool.

However, this does not mean that every patient needs endoscopy or colonoscopy. An endoscopic examination performed on the right patient, for the right indication and with proper preparation is an important part of the diagnostic and treatment process.

For this reason, the need for endoscopy or colonoscopy should be determined by evaluating the patient’s age, complaints, family history and other risk factors together.

Information Note

This content has been prepared for general information purposes. It is not a substitute for diagnosis or individual treatment advice. The need for endoscopy and colonoscopy should be determined by evaluating the person’s complaints, age, family history and other medical characteristics.

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