MANILA -- Colon cancer is fourth among the top causes of cancer-related deaths in the world and the rate is going up even in the Philippines, according to Dr. Juliet Gopez-Cervantes.

In dzMM's "Magandang Gabi Dok," Gopez-Cervantes, a gastroenterologist and hepatologist, explained that colon cancer is a cancer in any part of the 1.5 meter-long large intestine that processes waste that goes out through the rectum.

"Kapag namamaga ang colon o 'yung large intestine, nagkakaroon ng diarrhea kasi 'di naaabsorb ang water."

Colon cancer has four stages:

Stage 1

- The tumor is localized and is only on the surface of the colon. It is usually found as incidental finding when a CT scan or colonoscopy is administered to the patient.

Stage 2

- The tumor goes deeper into the colon and invades lower layers of the large intestine.

Stage 3

- Lymph nodes (kulani) will be present.

Stage 4

- The tumor reaches other organs such as the liver, kidney, and bones.

The bad news is that the symptoms of colon cancer will only be noticeable once the tumor has already advanced.

"Kung ang tumor o ang cancer ay nasa left side ng colon, 'yung few centimeters magmula sa anal opening... nagkakaroon ng manifestation ng pagbara ng daanan ng dumi kaya lumiliit ang dumi."

There will be instances when the patient will experience alternating bouts of diarrhea and constipation, blood stains on their stool, or loss of appetite that could lead to weight loss.

If the tumor is in the right side, one of its manifestation is anemia.

Unlike the tumor in the left side of the colon, bleeding won't be noticeable for those who has it on the right side.

Patients with ages 50 to 65 years old may experience weight loss and anemia might be showing signs of colon cancer.

Colon cancer is seldom painful unless it is already in an advanced stage.

"Seldom magbibigay ng pain unless bumara na ang isang tumor kunwari sa left side, lumaki na to the point na halos 'di na makalabas ang dumi, lalaki ang intestine to the point na lalaki ang tiyan, magbibigay ng abdominal pain, vomiting, at kadalasan walang lumalabas na hangin o dumi man."

However, there is good news: colon cancer can be treated early and prevented.

Gopez-Cervantes said the tumor starts as a polyp (tissue) in the large intestine which can evolve and develop into colon cancer.

If it is immediately seen by the doctor, it can be removed to prevent it from growing.

"Kung nakita siya during colonoscopy which is the direct visualization of the inside of the colon, 'pag nakitang may polyp o lamang tumutubo, kayang-kayang tanggalin right there and then lalo na kung 'di gaanong kalakihan and that will save the patient from colon cancer."

She reminded everyone to get checked, especially those who already reached 50 years old because 20 to 30 percent of their population produce polyps which can lead to cancer in five to 10 years.

People who have a family history of colon cancer or those who have immediate family members who had polyps removed from their colon should undergo screening when they reach 40 to 45 years old.