For many adults, colonoscopy is one of the most important health screens they will have during their lifetime. 

For Val Gueorguiev, it proved to be life-saving.

Gueorguiev had his first colorectal cancer screen in 2016, when he was 58. At the time, the recommended age to begin colorectal screening was 50 – it since has been lowered to 45.

He was presented with options for the screen – either a colonoscopy, which is a visual examination of the rectum and the entire large intestine to check for abnormalities, or a sigmoidoscopy, which only looks at the lower one-third to one-half of the colon and the rectum.

Gueorguiev, now 67, chose to have a sigmoidoscopy because it seemed safer and easier, he said, and it doesn’t require sedation as a colonoscopy does. 

During the exam, his UCLA Health gastroenterologist, Kevin Ghassemi, MD(Link opens in new window), identified a polyp on the left side of his colon – a growth on the inner lining that, if not removed, could potentially change into cancer over time. Dr. Ghassemi removed the polyp during the sigmoidoscopy, but he also recommended that Gueorguiev have a colonoscopy as soon as possible to see if there were any other polyps in the rest of the colon that could not be seen by the sigmoidoscopy.

It wasn’t until 2022 – six years later – that Gueorguiev took his physician’s advice.

Silent killer

The American Cancer Society(Link is external) (Link opens in new window) estimates 107,320 people in the U.S. will be diagnosed with colorectal cancer(Link opens in new window) in 2025. It is the third most common cancer in men, and the third most common cancer in women; it also is the second-leading cause of cancer deaths when numbers for men and women are combined.

Colorectal cancer is often called a silent killer because it is asymptomatic, meaning people can have it for years before any symptoms develop.

Regular screening can reduce the risks of developing colorectal cancer dramatically, says Dr. Ghassemi, who is clinical chief at the Melvin and Bren Simon Digestive Diseases Center at UCLA Health and medical director of clinical programs at the Robert G. Kardashian Center for Esophageal Health.

“To me, the name of the game is not just about finding cancer, but trying to find polyps,” Dr. Ghassemi says. “And getting them out before they become cancer. Because once you have cancer, then you're maybe going to need surgery or chemotherapy. It's not going to be an easy journey.”

Advantages of colonoscopy

Colonoscopy is the preferred screening method because it gives a direct look at the entire colon and offers the ability to remove polyps during the procedure, Dr. Ghassemi says. If the screen is normal, it also offers the longest interval between screening exams, at 10 years.

He notes that sigmoidoscopy has been likened to “half of a colonoscopy, so there is the potential for missing abnormalities on the right side, or upstream, part of the colon.”

Some patients are reluctant to undergo colonoscopy because of the required preparation (drinking a laxative to clean out the bowels) and the need to be sedated during the procedure, which can potentially lower the blood pressure or the heart rate and requires someone to drive the patient home afterward, he adds. 

Although sigmoidoscopy is an acceptable type of screening, and “any screening is better than no screening,” Dr. Ghassemi says, “it’s about what you’re willing to do for good health care.”

Life-saving procedure

By 2016, Gueorguiev had been walking around without ever having the right side of his colon evaluated. He was very busy, he reasoned, and his health had always been good. He saw no reason to have that colonoscopy Dr. Ghassemi had recommended.

“I was thinking everything was OK,” he says.

But it wasn’t OK. 

Six years after his sigmoidoscopy, Gueorguiev was overdue for another colorectal cancer screen. After getting a referral from his primary care physician, he called Dr. Ghassemi’s office to schedule a sigmoidoscopy. 

This time, he was told he must have a colonoscopy.

“After I reviewed the prior report and the pathology, I told him I can’t, in good conscience, order a sigmoidoscopy,” Dr. Ghassemi recalled.

Gueorguiev was impressed with the amount of time the doctor spent explaining the importance of what he was recommending.

“I realized that he’s a busy guy, and spending so much time with me there must be a good reason for it. So he convinced me to have the procedure,” he says.

In October 2022, Dr. Ghassemi performed the colonoscopy and identified and removed a large polyp on the right side of his patient’s colon. A biopsy showed the polyp had a high-grade precancerous dysplasia, meaning there were abnormal cells on the inner lining of the polyp.

Once those cells invade the deeper layers of the polyp or the wall of the colon, they become cancer, Dr. Ghassemi explains. The progression rate depends on many factors, including age, genetic predisposition, lifestyle and overall health of the patient.

The doctor notes that it was fortunate a polyp was identified on the left side of his colon during the sigmoidoscopy because it prompted the recommendation to proceed with a full colonoscopy.

He adds that because the pre-cancerous polyp found in 2022 was on the right side of the colon, it would have been missed with a sigmoidoscopy.

“I think this highlights the potential added value of doing a full colonoscopy to look at the entire lower GI tract,” he says.

‘It pays to know’

Today, Gueorguiev says he’s extremely grateful Dr. Ghassemi took the time to explain the procedure for colonoscopy in detail and make him feel comfortable and confident with the process.

He’s so grateful that he still has the phone message from Dr. Ghassemi’s initial call. And Gueorguiev even convinced his wife and several friends to have colonoscopies.

“If I had waited longer, most likely it would be a completely different story,” he says. “It was life-saving, in my opinion.”

Gueorguiev had a follow-up colonoscopy in December 2024. A benign polyp was identified and removed, and he won’t require another colonoscopy for five years.

His advice for others who are recommended for a colonoscopy?

“Even if you think that you’re perfectly healthy, as I was thinking, it pays to know,” Gueorguiev says. “And when the doctor tells you to do it, I'm 100% convinced you should do it. Because there's a really good reason for the doctor to recommend it.”