How to do colorectal cancer screening during physical examination

Colorectal cancer screening can be performed through fecal occult blood test, colonoscopy, fecal DNA testing, CT colon imaging, sigmoidoscopy, and other methods. Colorectal cancer is usually caused by genetic factors, high-fat and low fiber diet, chronic inflammation of the intestine, malignant transformation of adenomatous polyps, long-term smoking and alcohol consumption, and other reasons.

1. Fecal occult blood test

Fecal occult blood test is a method of detecting trace amounts of blood in feces to determine whether there is bleeding in the intestine. This method is easy to operate and non-invasive, suitable for initial screening of large-scale populations. If the result is positive, further colonoscopy examination is required. However, it should be noted that benign diseases such as hemorrhoids and anal fissures may also lead to false positives.

2. Colonoscopy

Colonoscopy is the gold standard for diagnosing colorectal cancer, which can directly observe the lesions of the entire colon mucosa and take a biopsy. Before the examination, it is necessary to prepare for intestinal cleansing, which may be accompanied by bloating and discomfort during the process. This examination can detect early cancerous changes and precancerous lesions, and it is recommended for people over 50 years old to undergo it every 5-10 years.

3. Fecal DNA testing

Fecal DNA testing screens for tumors by analyzing gene mutations and methylation abnormalities in shed cells in feces. This method has high specificity and can detect early cancerous signals. But the price is relatively expensive, and currently it is mostly used for supplementary screening of high-risk groups who cannot tolerate colonoscopy examination.

4. CT Colonoscopy

CT Colonoscopy uses three-dimensional reconstruction technology to display the structure of the colon, which is suitable for those who cannot tolerate traditional colonoscopy examination. Before the examination, it is also necessary to clean the intestines, which can detect larger polyps and tumors, but has lower sensitivity to flat lesions. This examination poses a risk of radiation exposure and is not recommended as a routine screening method.

5. Scolioscopy

Scolioscopy can observe the rectum and part of the descending colon, with a short operation time and low requirements for intestinal preparation. The detection rate of distal colon lesions is relatively high, but proximal colon lesions may be missed. It is recommended to conduct a joint fecal occult blood test for screening every 5 years, which may be considered for areas with limited economic conditions.

It is recommended that people over 40 years old undergo regular screening for colorectal cancer, and those with a family history or intestinal symptoms should be screened for age in advance. Maintaining a high fiber diet in daily life, limiting intake of red meat and processed meat products, quitting smoking and limiting alcohol consumption, and regular exercise can help reduce the risk of disease. If abnormalities are detected during screening, timely medical treatment is necessary, and the cure rate for early colorectal cancer can reach over 90%.