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Colonoscopy for Early Colorectal Cancer Screening: When is it Necessary?

Medical experts assess colorectal cancer as a prevalent malignancy, ranking high in mortality rates, only second to stomach, liver, and lung cancers. Therefore, early detection of colorectal cancer holds significant importance in successfully treating this condition. Currently, colonoscopy is evaluated as the primary method for screening and supporting effective treatment of gastrointestinal diseases, including colorectal cancer. Let’s delve into the details of “When is colonoscopy for early colorectal cancer screening necessary?” in the following article.

1. Significance of Colonoscopy in Colorectal Cancer Screening

Colonoscopy is a method that allows physicians to observe the inside of the colon most effectively to screen for colorectal cancer and detect colon polyps. During a colonoscopy, a flexible tube with a small camera attached is inserted into the colon through the anus. The camera enables clear observation of the colon’s inner lining, aiding in the detection of abnormalities such as inflammation, polyps, or tumors. Upon detecting these abnormalities, physicians can perform biopsies or remove them during the colonoscopy procedure for further examination to determine their nature (whether they are malignant or benign cells).

Colonoscopy for Early Colorectal Cancer Screening: When is it Necessary?

Colonoscopy is an essential diagnostic tool for colorectal cancer screening.

2. Common Colonoscopy Methods

Currently, there are two common colonoscopy methods for colorectal cancer screening: non-sedated colonoscopy and sedated colonoscopy.

2.1. Unsedated Colonoscopy


Lower cost due to the absence of sedation expenses; patients remain fully awake during the procedure.


Patients may experience discomfort, nausea, or bowel stimulation during the procedure due to being fully awake, potentially affecting the colonoscopy process.

2.2. Sedated Colonoscopy


– Sedation eliminates discomfort, nausea, and bowel stimulation, facilitating a smoother colonoscopy process and providing accurate and quicker diagnostic results.

– Reduces patient anxiety, minimizing complications during the procedure due to patient distress.


– After the colonoscopy, patients need to stay in the recovery room for the physician to monitor their health status post-sedation.

– Some patients may experience side effects from the sedation medication, which typically resolve shortly afterward. Additionally, patients undergo pre-sedation medical assessment to minimize potential dangerous complications.

Colonoscopy for Early Colorectal Cancer Screening

Most patients receive an intravenous sedative to promote relaxation and minimize discomfort during the procedure.

3. When to Undergo Colonoscopy for Early Colorectal Cancer Screening

3.1. Presence of Warning Signs of Colorectal Cancer

Individuals should undergo colonoscopy for colorectal cancer screening when experiencing the following symptoms:

– Persistent abdominal pain or cramps over an extended period in the lower abdomen.

– Digestive disorders such as prolonged diarrhea or constipation, dark-colored stool mixed with blood or mucus.

– Loss of appetite, aversion to food, accompanied by indigestion, bloating, or discomfort in the upper abdomen.

– Rapid weight loss and unexplained anemia.

– Feelings of exhaustion, fatigue, even after adequate rest, accompanied by rapid physical weakness without apparent cause.

These warning signs may indicate the presence of dangerous colorectal cancer. At this point, patients should promptly seek medical attention without delay.

3.2. Belonging to High-Risk Groups for Colorectal Cancer

For individuals belonging to high-risk groups for colorectal cancer, experts recommend early cancer screening for effective disease prevention. These groups include:

– Individuals with a medical history related to the colon (colitis, colon polyps, Crohn’s disease, etc.) or family members (parents, siblings) who have had colorectal cancer.

– Individuals with hereditary syndromes, among which the most common are Lynch syndrome (hereditary non-polyposis colorectal cancer) and familial adenomatous polyposis (FAP).

– Individuals with unhealthy lifestyles such as poor dietary habits, excessive tobacco or alcohol use.

– Individuals over the age of 50.

– Nevertheless, even for healthy individuals without specific disease symptoms, starting from the age of 30, regular colonoscopies are recommended for early detection and control of colorectal cancer.

When is Colonoscopy for Early Colorectal Cancer Screening Necessary

Individuals with a medical history involving colon-related diseases are at an elevated risk of developing colon cancer

4. Colonoscopy Preparation Tips

Before undergoing colonoscopy, individuals should note the following precautions to ensure accurate results and a smooth colonoscopy process:

– Consume light, low-fiber foods for approximately four days before colonoscopy to help cleanse the colon and facilitate observation.

– Drink plenty of water and avoid colored beverages about one day before colonoscopy.

– Use strong bowel cleansing medications to cleanse the digestive tract the night before colonoscopy. From the time of taking the medication until the colonoscopy, patients must refrain from eating entirely.

– In some cases, physicians may request patients to stop taking certain medications (iron supplements, blood thinners, diabetes medications, etc.) before and on the day of colonoscopy.

In conclusion, colonoscopy plays a vital role in early colorectal cancer screening. Therefore, even in the absence of warning signs, individuals should proactively undergo regular colorectal cancer screening to monitor their health status and promptly detect any abnormal signs for effective treatment.

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