Colon cancer

3 minute(s) read

Bangkok Rayong Cancer Hospital

Updated on: 10 Dec 2025

Types of cancer
Cause
Symptom
How many stages are there in cancer?
Screening methods
Treatment method
Preparation before undergoing examination

What is Colon Cancer?

The colon and rectum are part of the digestive system. They are long tubes that absorb water from food eaten and store waste before it is excreted from the body through the rectum.
Colon cancer can occur at any age. Common warning signs of colon cancer include blood in the stool, weight loss, and chronic inflammation of the bowel.
Colon cancer typically occurs in people 50 years of age and older. By the time most patients are diagnosed with colon cancer, it is usually already at an advanced stage, which increases the risk of death. Therefore, screening for colon cancer prevention or seeking medical attention as soon as symptoms appear is the best prevention.
Colon cancer is a cancer that begins in the lower part of the digestive system, the third most common cancer and the second leading cause of death in Thailand.

Causes of Colon Cancer

Genetic inheritance: Parents, siblings, and direct descendants

A history of colon polyps. High-risk individuals are more likely to develop colon cancer.
Patients with chronic inflammatory bowel disease
A history of previous illnesses, such as ovarian, uterine, or breast cancer, is also more likely to develop colon and rectal cancer.
People over 50 years of age
Eating a diet high in fat
Eating meat or red meat that has been cooked excessively for too long
Ingesting toxins and retaining them in the intestines.
Toxins are often found in grilled, roasted, pickled, and fermented foods, as well as chemicals from unclean vegetables
People with a history of alcohol consumption or smoking
People who are obese, especially those with a BMI above normal (over 25 or a waist circumference of over 36 inches)

Colon Cancer Prevention

Cancer screening should begin at age 50 for normal individuals. People with a family history of cancer shoul begin screening at age 40 or older.
Exercise regularly, eat a diet high in fiber, such as vegetables and fruits, and avoid foods high in fat.

What are the symptoms of colon cancer?

Bloating, constipation, or alternating diarrhea.
Blood in the stool.
Rectal bleeding.
Small or thin stools
Frequent heartburn, fullness, or abdominal pain.
Pale, fatigue, and unexplained weight loss.
A palpable mass in the abdomen, usually in the lower right quadrant.
Painful rectal pain, similar to the constant need to have a bowel movement.
No symptoms.

How many stages are there of colon cancer?

Stage 1: Cancer is confined to the colon wall.
Stage 2: Cancer has spread beyond the colon wall to nearby areas.
Stage 3: Cancer has spread to nearby lymph nodes.
Stage 4: Cancer has spread to nearby organs, such as the lungs and liver.

Early Screening for Colon Cancer

Sigmoidoscopy and Colonoscopy
Computed Tomography (CT) Colonography
Barium Enema
Twice-Yearly Stool Blood Tests

Treatment for Colon Cancer

Surgery is the best option after a doctor has detected a tumor in the colon during a colonoscopy and surgery is necessary.
Chemotherapy
Radiation Therapy

Is Colon Cancer Curable?

Colon cancer has a better cure rate and prognosis than liver and lung cancer. Especially if colon cancer is detected in stages 1 or 2, the goal of treatment is complete cure. If the cancer is stage 3 or 4, the cure rate is even lower.

Preparing for Colon Cancer Screening

Patients must prepare by eating a low-fiber diet and taking laxatives 1-2 days before the examination. Anesthesia and pain medication will be administered during the procedure. The colonoscopy lasts approximately 30-60 minutes. After the procedure, you may feel dizzy from the anesthesia and experience some mild bloating.