Scott Webb (Host): The age of 50 used to be the magic number for most of us to have our first colonoscopy, but guidelines have changed. And my guest today is here to update us on the guidelines, assure us that the prep isn't as bad as it used to be, and more. I'm joined today by Dr. Mamta Mehta. She's a board-certified gastroenterologist with Eisenhower Health.

This is Living Well with Eisenhower Health. I'm Scott Webb. Doctor, it's nice to have you here today. We're going to talk colonoscopy. And there's never really a bad time to talk colonoscopy, but we want to encourage folks to be screened. And I know that the guidelines have changed in recent years. So, maybe let's start there. Let's kind of review the guidelines, when folks should be screened, at what age, and so forth.

Dr. Mamta Mehta: Well, Scott, thank you for giving me the opportunity to talk about this very important subject. This is a great place to start. So, let's first just talk about the facts, so that we understand why colorectal cancer screening, or also called colon cancer screening—I may use that interchangeably—is important and why the guidelines have recently changed.

So, as we know, colon, colorectal cancer is the third most common cancer that's diagnosed in both men and women in the United States, and even more importantly, it is the second most common cause of cancer deaths when numbers of men and women are combined. So for 2026, the American Cancer Society has estimated that the number of colorectal cancers to be diagnosed are about 158,000 new cases in both men and women.

But here's a little silver lining. The rate of the people being diagnosed with colorectal cancer has dropped overall since the mid-1980s, mainly because more people are getting screened and they're changing their lifestyle-related risk factors. But, but, but this downward trend is mostly in older adults. In people younger than the age of 50, the rates have increased by almost 3% per year between the years of 2013 and 2022.

So as a result, in 2018, the American Cancer Society independently updated the guidelines. It became the first major organization to lower its recommended initial screening age from 50 years of age to 45 years of age. So, that's why it's important to understand that background and why the medical community did what we did. And so, the US Preventative Services Task Force, which is an independent volunteer panel of national experts changed their recommendations in 2021, making 45 the standard baseline age for average-risk individuals.

And then, shortly after, the US MultiSociety Task Force, represented by the American College of Gastroenterology, the American Gastroenterological Association, and the American Society of Gastrointestinal Endoscopy, updated their screening—their 2017 colorectal cancer screening recommendations—to suggest average risk colon cancer screening should begin at the age of 45 years.

Host: Right. Yeah. So, you give us some background there and why it used to be 50 was the magic number. Now, it's really 45. And as you say, younger people are being diagnosed. So, we want to get folks in there and get them screened. How does someone know, Doctor, if they're at high risk?

Dr. Mamta Mehta: High-risk timelines can vary significantly, and it's dependent on one specific medical history and their genetic factors. So, let's talk about family history. So on average, a family history of colorectal cancer is believed to be associated with a twofold increase in colorectal cancer, particularly in patients with first-degree relatives below the age of 60 years.

So, the magnitude of one's risk for colorectal cancer screening depends on their age, the age of the diagnosis of their relative, and the degree of the familial relationship between the individual and the relative, whether they're a first-degree or a second-degree relative. So, high-risk screening, it applies to anyone with a first-degree relative, such as a parent, sibling, child, who's diagnosed with colorectal cancer before the age of 60, or two or more first-degree relatives diagnosed at any age.

And so, if you have that background family history, we recommend that colorectal cancer screening begin at age 40 or 10 years prior to the youngest affected relative's diagnosis. Now, anyone with a first-degree relative, who developed colorectal cancer after the age of 60, we also recommend starting colorectal cancer screening at age 40. But then, average risk screening guidelines are applied after their first colon cancer screening examination.

Host: Right. Yeah. So, I was saying, 50 was the magic number, then it became 45. And if you have a family history, 40 or possibly 10 years as you've explained there. So, great information. And I know, Doctor, that a lot of times when folks have colonoscopies, they're told that they have polyps, right? Or polyps that were found. What is a polyp exactly? And why is it important that you find them and that you remove them?

Dr. Mamta Mehta: That's a question I get all the time in the office. And it's really important that we discuss that. So, colon polyps are small little abnormal growths that develop on the superficial lining of the large intestine, otherwise the colon and the rectum. While the majority of them are benign, some precancerous types can eventually develop into colorectal cancer if they're not detected or removed. So, the colon lining is rapidly turning over. Polyps form when the typical cycle of cell growth and repair go off track. So instead of dying off and being replaced in an orderly fashion, these extra abnormal cells start to multiply, build up into bumps or growths. And those are particularly what we look at and remove when we see them during a colonoscopy.

Host: Yeah, I'm wondering, Doctor, you know, when those patients with polyps—it sounds like a lot of us, of course—but those patients with polyps, do they need to be screened more often? Is that some sort of cue for that, or does it depend?

Dr. Mamta Mehta: Great question. So, let's talk about patients who don't have polyps found. So if you had a high-quality colonoscopy, and no polyps were found, the patients with no polyps are considered lowest risk for colorectal cancer. And those with polyps are risk stratified based on the number of polyps, the size of the polyps, and what they look like under the microscope, or what we call histology.

So, a history of polyps may increase the risk of an advanced polyp or colorectal cancer in the future. But the interval that we suggest after the first colonoscopy is dependent on these three factors: what the polyps look like under the microscope, the number, and the size of the polyps

Host: Right. If a patient, Doctor, is told that they had a good outcome on a colonoscopy, yay, right? And that they won't have to have another one for 10 years, is there a point, any point, do folks just kind of stop needing them? Do we at some point effectively age out of colonoscopies?

Dr. Mamta Mehta: Yeah. So, this is a great question and often requires a patient-provider deep discussion. So, we know that the risk of advanced colorectal polyps and colon cancer increases with age. However, we have to keep in mind that the prevalence of medical comorbidities or other medical problems and overall mortality or risk of death also increases with advanced age.

So, previous guidelines have recommended to continue screening until age of at least 75 years when clinically appropriate. But individuals without a history of prior screening may benefit in this setting. So, the decision to initiate or continue screening after the age of 75 should involve a shared decision-making process between the patient and provider and consider prior screening history, their life expectancy, and patient preferences.

Patients really emphasize provider trust, perceived health risks, barriers to screening, and perceived colorectal cancer risk in this whole decision-making process. So, it is a discussion I encourage individuals to have with their provider before they decide to continue or start colorectal cancer screening if they haven't been screened at an earlier age. So now, individuals after the age of 85 are typically not offered colorectal cancer screening because the overall mortality risk and the risk of adverse events associated with the colonoscopy may outweigh the life expectancy benefit of removing polyps in this age group. We have to keep in mind it's still a procedure and that unintended harms can happen from screening and is higher in the elderly population.

Host: Yeah, it's a lot to take in here and it's great to have you on, great to have your expertise. And I want to talk about prep. Nobody wants to talk about prep. Nobody wants to do prep. But it does seem to me, in my own personal experience, that it's gotten a little easier over the years, a little less volume of the prep. And I just want to get a sense from you, like, is that true? Like, am I just imagining this or is it a little easier than it used to be, a little more tolerable for folks? And then, maybe tell folks like why it's so important, why we have to do the prep, why it must be done correctly and all of that.

Dr. Mamta Mehta: So, a common barrier is the colon bowel prep, and I will reassure you that it has evolved to become much easier, less restrictive, and more tolerable. So, the days of drinking a gallon of foul-tasting liquids all at once and fasting for days are mostly gone. So here are some of the major changes, to the colonoscopy prep.

So, number one, there is a split dosing. So instead of taking all the laxative the night before, the standard is now doing a split prep. So, you drink half of the bowel prep the night before, and then the second half about four to six hours before your procedure. This significantly reduces nausea, prevents the overnight discomfort, and results in a cleaner colon, particularly the right colon.

There are also now lower volume bowel preps available. So for most average-risk patients, the standard four-liter gallon prep has been replaced by smaller two-liter options. There is a pill alternative. There's an FDA-approved pill-based prep such as a brand called Sutab, which is available. Patients have to take a total of 24 pills, however. That's split across two doses, along with plenty water. So, it's not easy. But also, the shorter, less restrictive diets. A prolonged multi-day fasting is no longer recommended for most patients. A low fiber, low residue diets can be eaten up to the day before the procedure.

Host: Yeah. Why is it so important from your perspective, literally, that we do the prep, that we do it properly? Does it make screening just easier, more effective, all of that?

Dr. Mamta Mehta: So, a cleaner colon results in a high-quality examination. When we visualize the lining of the colon, if the colon is not clean, it's much more difficult for us to optimally evaluate the lining of the colon and look for polyps that may be subtle, that may blend into the background of the normal tissue. And so, doing the prep correctly is very important to result in a high-quality examination.

Host: Of course. And we talked earlier about family history and the fact that younger are being diagnosed kind of alarmingly now than it used to be the case. So, let's just sort of tie these together. Are there some signs and symptoms that maybe younger patients should be aware of, should bring to the attention of their primary care doctor so that they, you know, can move up that screening timeline maybe perhaps, especially with a family history? Sort of bring those things together for us and give us a little clarity.

Dr. Mamta Mehta: Yes. I always say you know your body the best. So if there are any questions about any changes in your normal baseline bowel function, always discuss with your primary doctor. But the key warning signs that suggest that you should see a gastroenterologist include unexplained rectal bleeding, persistent changes in bowel habits, chronic abdominal pain, and unexplained iron deficiency anemia.

Host: Okay. Yeah. So, some things that, you know, we all need to be aware of, of course, know our family history, look out for some of the signs and symptoms. Of course, speak with our primary care doctors, be referred, get those colonoscopies, all good stuff. Just wondering if you have any thoughts about why we might be seeing this increase in younger people. Is it diet? Is it the rise of obesity? Like, do you have any sense? Like, how do we answer that question basically? Like, why are more younger people being diagnosed?

Dr. Mamta Mehta: So, nobody knows for sure why colorectal cancer numbers are rising in young people. However, leading theories suggest there are several factors that contribute to this rise. So, number one, the diet and the gut microbiome. Heavy consumption of our ultraprocessed foods, high-sugar drinks, and red meats can alter the gut microbiome.

So, this creates a chronic inflammation. It can release toxins that damage the DNA, and they pave way for tumor growth. Additionally, obesity and metabolic changes, lack of physical exercise alter the hormone levels and increase the body's inflammatory response, which are strongly tied to colorectal cancer risk.

And thirdly, the environmental exposures. I mean, there's growing research that suggests that early life exposures to toxins, pesticides, microplastics may disrupt the normal cellular or bacterial function of our gut.

Host: Okay. Yeah, and I'm sure research is ongoing, but the important point we're trying to make here today is that younger folks, if they have the risk factors, family history, so forth, speak with your doctors, get screened. And let's just finish up there, Doctor. Let's just emphasize the importance of being screened, whether it's 40, 45, 50, after 50. Why is it so important?

Dr. Mamta Mehta: So, colorectal cancer screening is very important because, in the early stages of colorectal cancer, it can rarely cause symptoms. So if caught early, you have a higher likelihood of being cured. It catches the existing cancer at its earliest, most treatable stages when the five-year survival rate can exceed over 90%. By the time someone does develop symptoms, it may be found at a late stage, which is significantly harder to treat. So, screening dramatically improves the survival rate.

Host: Yeah. So true. And as is the case with all cancers, of course, early diagnosis is really beneficial to patients. But in this particular case, because screening is so effective, the removal of polyps is so key. We want to get everybody to speak with their doctors to be screened. And, Doctor, I just really appreciate your time today. Thank you so much.

Dr. Mamta Mehta: Thank you so much for having me, Scott. Appreciate it.

Host: And for more information, go to eisenhowerhealth.org/services/digestive. And if you found this podcast helpful, please share it on your social channels and check out the full podcast library for additional topics of interest. I'm Scott Webb. And this has been Living Well with Eisenhower Health. Thanks for listening.