Robin Gibb Cancer: What Are The Causes And Symptons Of Colorectal, Colon Cancer?

Robin Gibb, one third of the musical trio, the Bee Gee's, has been diagnosed with colorectal cancer.

Gibb remains in intensive care after waking from a coma on April 22, according to USA Today.

Although the singer caught pneumonia in the midst of his diagnosis, he was further weakened by intense doses of chemotherapy and two operations, which doctors say may have led to the deep state of unconsciousness.

Colorectal cancer, also known as bowel cancer, is caused by uncontrolled cell growth in the colon or rectum. Symptoms typically include rectal bleeding and anemia, which are sometimes associated with weight loss and changes in bowel habits, according to the American Cancer Society.

Doctors stress the importance of screening for the disease, as colorectal cancer is the third most common cancer diagnosed in both men and women in the United States.

The American Cancer Society most recently estimates 103,170 new cases of colorectal cancer cases in the United States, for the year 2012.

Gibb, 62, falls correctly in to the age group of men and women most likely to receive a colorectal cancer diagnosis, as the people who are said to be at a higher risk are those at an age older than 60.

But while the death rate from colorectal cancer has been dropping for more than 20 years, regular colorectal screening or testing is one of the most powerful weapons for preventing the disease, according to the ACS.

Commons studies suggest that before colorectal cancer actually develops, a growth of tissue of tumor usually begins as a non-cancerous polyp on the inner lining of the colon or rectum.

If cancer forms within a polyp, it can eventually begin to grow into the wall of the colon or rectum. And while several types of cancer can start in the colon or rectum, more than 95 percent of the colorectal cancers are what doctor's call, adenocarcinomas.

According to the ACS, these most common types of cancers start in cells that form glands that make mucus to lubricate the inside of the colon and rectum.

As overall lifetime risk for developing colorectal cancer is about 1 in 20 (five percent), the possibility tends to be high in men than in women.

But because some polyps, or growths, can be found and removed before they have the chance to turn into cancer, regular screenings, in many cases, can prevent the disease altogether.

Gibb is still in intensive care and is exhausted, extremely weak and malnourished, Dr. Andrew Thillainayagam told USA Today.

Gibb is currently breathing with the help of an oxygen mask and is dependent on arterial feeding and antibiotics.

It is a testament to Robin's extraordinary courage, iron will and deep reserves of physical strength that he has overcome quite incredible odds to get where he is now, Thillainayagam said in a statement.

The Bee Gees - British-born, Australia-raised brothers Robin, Barry and Maurice are best known for their disco-era hits which include How Deep is Your Love, and Stayin' Alive.