Early Diagnosis of Stomach and Bowel Cancer Using the Staining Method

Early detection in stomach and bowel cancers is the most crucial step that determines the success of treatment. Chromoendoscopy, commonly known as the staining method, is an advanced diagnostic technique. During standard endoscopy and colonoscopy procedures, special medical dyes are sprayed onto the surface of the digestive tract, allowing cellular changes to become much more visible. This way, cells with a tendency to become cancerous or very early-stage tumors that are hard to spot with the naked eye can be easily detected, and pinpoint biopsies can be taken from suspicious areas.

• Chromoendoscopy is a specialized staining technique that distinguishes cancerous cells from normal tissue.
• It highlights cellular abnormalities that standard illuminated cameras might miss.
• It is a critical screening tool, especially for those over 50 and individuals with a family history of cancer.
• In countries like Japan, where this screening is widespread, early diagnosis rates reach up to 95 percent.
• The procedure takes only a few minutes longer than a standard endoscopy.

What is Chromoendoscopy (The Staining Method)?

The answer to what chromoendoscopy is lies in how the tissues on the surface of the digestive system are examined. Normally, during an endoscopy or colonoscopy, a doctor examines the lining of the stomach or large intestine using a flexible tube with a light and camera at the tip. However, some cellular changes on the tissue surface may look the exact same color as healthy tissue under normal light. This can easily lead to missing very early-stage flattened or slightly sunken lesions.

In the staining technique, harmless, specialized medical dyes are sprayed onto the organ's surface during the procedure. Healthy mucosal cells and cancerous or precancerous cells have different capacities for absorbing the dye. After the dye is applied, the surface is washed with a special fluid. While healthy tissues wash off the dye and return to their normal pink color, structurally altered cells hold onto the dye. As a result, cellular differences are revealed like a map, and the doctor knows exactly where to take a tissue sample.

Causes and Risk Factors in Stomach and Bowel Cancer

Although it is difficult to pinpoint a single cause for cancer development, certain genetic and environmental factors significantly increase the risk. Knowing who needs to be more careful forms the foundation of screening programs for these diseases, where early diagnosis is truly life-saving. According to extensive clinical data, it is highly important for individuals in the at-risk group within the community to have regular check-ups.

If you have one or more of the following factors, it is recommended that you consult your doctor to create a screening plan:

• Advanced age: Being 50-60 years old or older increases the risk of the disease.
• Genetic predisposition: Having a history of stomach or colon cancer in first-degree relatives (mother, father, sibling).
• Past medical findings: Having polyps detected in previous colonoscopies.
• Stomach infections: Having had and been treated for an infection caused by Helicobacter pylori bacteria in the stomach.
• Harmful habits: Long-term smoking and chronic alcohol consumption.
• Diet and metabolism: Excess weight (obesity), and a diet heavy in processed meats and excessively salty foods.

Symptoms of Stomach Cancer and Warning Signs of Bowel Cancer

Digestive system cancers often progress silently and may not cause any complaints in their early stages. The first symptoms that do appear are often ignored by patients, who might mistakenly think that indigestion or stomach complaints are caused by gastritis. However, taking the signals your body gives you seriously is a critical opportunity to catch the disease early.

The main warning signs caused by stomach cancer and tumors in the bowel system include:

• Rapid, unexplained weight loss without dieting or exercising.
• Unexplained, persistent, or increasingly severe abdominal pain.
• Feeling full early and experiencing bloating despite eating very small amounts of food.
• Seeing blood in your stool or having stools that are black and tar-like.
• Sudden and lasting changes in bowel habits (such as prolonged diarrhea or constipation).
• Unexplained anemia and the constant feeling of fatigue that develops as a result.

Diagnosis at the Hospital: How is Early Detection Done with the Staining Method?

Clinical statistics strikingly demonstrate the importance of early diagnosis. For example, in a large-scale clinical evaluation covering approximately 25,000 cases, early stomach cancer was caught in only 61 cases using standard methods. While the rate of catching stomach cancer at an early stage remains around 1-2 percent in Türkiye and Western countries, this rate reaches 95-98 percent in Japan, where screening culture and advanced techniques like chromoendoscopy are widespread. This proves just how decisive the use of the bowel cancer staining method and advanced technological devices can be.

The diagnostic process at the hospital begins with the patient's pre-procedure preparation. If the colonoscopy staining technique is to be applied, the patient is given bowel-cleansing medication a day in advance. On the day of the procedure, the patient is placed in a light sleep (sedation) so that they feel absolutely no pain or discomfort. The doctor enters with the endoscope, spraying the special dye over wide areas that look suspicious. Mapping is done based on how the tissues absorb the dye, and millimeter-sized biopsies are taken from points that remain a different color and have a disrupted structure. These samples are then examined in the pathology laboratory to make a definitive diagnosis.

Treatment Approaches for Cancers Caught in the Early Stage

Catching cancer cells while they are still in the most superficial layer of the organ—before they advance into deeper tissues—completely changes the treatment process. When diagnosed early, the patient may not need to undergo major, exhausting surgeries. Using only endoscopic methods (EMR or ESD techniques), the cancerous tissue can be peeled off the surface without disrupting the integrity of the organ. This way, the patient's stomach or bowel is not removed, and digestive functions are preserved.

If the tumor has progressed slightly but is still in its early stages, surgical intervention may be required. However, surgeries performed at this stage are much more limited and conservative. The patient's recovery time is shorter, and the hospital stay is reduced. Furthermore, the likelihood of needing additional treatments like chemotherapy or radiotherapy is quite low for early-stage tumors. Patients return to their normal lives much faster after treatment, and long-term survival rates are close to perfect. Sometimes patients may confuse their symptoms with benign conditions like irritable bowel syndrome; therefore, staining endoscopy provides great reassurance for a differential diagnosis.

Risks and Complications of Delayed Diagnosis

Neglecting screening programs and ignoring symptoms cause the disease to progress to advanced stages. As digestive system cancers move into deeper layers, they carry the risk of spreading (metastasizing) to the lymph nodes and from there to distant organs like the liver and lungs. In cases of delayed diagnosis, the tumor can block the inner cavity of the organ, leading to bowel or stomach obstructions.

In advanced stages, surgical interventions must be much more extensive. A large part or all of the organ may need to be removed. Additionally, long-term chemotherapy and radiotherapy sessions, which have heavier side effects, become mandatory before or after surgery. This entire process severely lowers the patient's quality of life while significantly reducing the success rate of treatment compared to the early stage.

When to See a Doctor?

Although digestive system issues are common, certain symptoms are 'red flag' signs that require immediate medical evaluation. You need to listen to your body to understand whether your complaints are a simple digestive issue or a harbinger of a serious illness. If you experience any of the following conditions, you should apply to a healthcare facility without wasting time:

• Sudden, very severe, and agonizing abdominal pain.
• Vomiting blood that looks like coffee grounds or is bright red.
• Stool that is pitch black like tar, sticky, and foul-smelling.
• Severe dizziness, blackout, and a feeling of fainting (which can be a sign of sudden bleeding).
• Severe constipation and abdominal bloating lasting for days, without even passing gas.

In the event of such sudden and severe symptoms, you should call 112 to request emergency assistance or visit the emergency department of the nearest hospital.

The Process at BHT CLINIC İstanbul Tema Hastanesi

At our hospital, the diagnosis and treatment of digestive system diseases are carried out with a multidisciplinary approach by our expert medical staff and advanced technological equipment. Specialized procedures like chromoendoscopy are safely performed under sedation by our experienced gastroenterology and general surgery specialists, keeping patient comfort at the highest level. In emergencies such as sudden bleeding or severe pain, our Emergency Medicine department, which provides uninterrupted service 24/7, quickly performs all necessary first aid and directs our patients to the relevant specialty branches.

To avoid leaving your health to chance and to create your screening plan if you are in the risk group, you can book an appointment with our specialist doctors.

Frequently Asked Questions

Who is chromoendoscopy performed on?

It is applied at a doctor's discretion to individuals with a family history of stomach or bowel cancer, those over 50, patients who have had polyps detected before, and people in the risk group with complaints like unexplained weight loss or abdominal pain.

How long does a colonoscopy with the staining method take?

The procedure is only a few minutes longer compared to a standard colonoscopy. The process of applying the dye, washing it, and examining the area is generally completed in 20 to 30 minutes in total.

Is pain felt during the procedure?

No, during the procedure, the patient is given mild sleep-inducing and relaxing medications (sedation) intravenously. The patient sleeps throughout the procedure and does not feel any pain, cramps, or discomfort.

If stomach cancer is diagnosed early, is it completely cured?

Yes, if cancer cells are caught while they are only on the uppermost surface of the organ, the disease can be completely cleared from the body with endoscopic or minor surgical interventions, allowing the patient to live a normal, healthy life.

Are the medications used in the staining technique harmful?

The dyes used are special solutions for purely medical purposes that do not harm human tissue. They are not absorbed by the body and are safely excreted through the stool after the procedure.

This article is for informational purposes only; please be sure to consult your doctor for diagnosis and treatment.