What many dismiss as harmless hemorrhoids – or just too much time on the toilet – can sometimes be an early warning sign of something more serious.

Dr. Anne Lin – a practicing colorectal surgeon and a health sciences clinical professor of surgery in the David Geffen School of Medicine – discussed health risks, misconceptions and new advancements for colorectal cancer awareness month.

Lin received her medical degree from Tufts University and has been practicing for over two decades. She received a Master of Public Health degree from the Fielding School of Public Health and joined the department of surgery at UCLA in 2011.

This interview has been edited for length and clarity.

Daily Bruin: Colorectal cancer is increasingly being diagnosed in younger populations. What is driving this trend, and why is it particularly concerning?

Anne Lin: Since the 1990s, we’ve seen a steady increase in colon cancer diagnoses amongst people under 50, and in some age groups – particularly those in their 20s and 30s – the rates have been rising by about 2-3% per year. So while the overall risk is still lower than in older adults, this upward trend is unmistakable. About one in 10 colorectal cancer cases are occurring in people under 50 and that proportion is growing. It’s concerning in that younger patients are more likely to be diagnosed at a later stage, often because screening isn’t routine for them and symptoms can be overlooked or misattributed.

I should say there’s no single cause but several factors seem to be contributing, and so one of these is lifestyle changes. There’s higher rates of obesity, diets rich in processed foods and red meat, lower levels of physical activity. So these factors can influence inflammation and metabolic health, both of which are linked to cancer risk. We’re also paying close attention to the gut microbiome – the community of bacteria in our digestive system.

DB: Many gastrointestinal symptoms are common, so how can someone distinguish between something benign and a potential warning sign?

AL: That’s a challenge, right? Because common conditions and serious ones can look very similar at first, but I think there are a few red flag symptoms that we should always prompt (for) medical evaluation. The most important one is rectal bleeding. People can assume that it’s hemorrhoids, which are common, but really we want to warn patients that they may need to have that checked out.

I always remind my patients and students to avoid prolonged sitting on the toilet because you know that can increase pressure in the rectal veins and increase risk of hemorrhoids. A simple alternative is to sit on the toilet seat lid or to stand up if nothing is happening because once you have bleeding, that can cause worry and concern. If there is bleeding, an early evaluation can be life saving.

DB: Are there any lifestyle risks, specifically dietary patterns, that can potentially increase or decrease risk, if there are any?

AL: Maintaining a healthy weight, staying active, focusing on eating plenty of fiber and fruits and vegetables and reducing red and processed meat, avoiding smoking and limiting alcohol – it’s really good for cancer prevention and supporting overall gut health. It’s not just the bleeding. Other symptoms you want to pay attention to are any changes in bowel habits that last more than two or three weeks, diarrhea, changes in stool caliber, abdominal pain, unexplained weight loss, fatigue (due to) iron deficiency anemia.

DB: When should people actually start thinking about colorectal cancer screening today?

AL: The guidelines have changed, so we’re starting screening at age 45 (instead of 50) for an average risk individual. A really important thing that I want to emphasize is to really know your family history. If you do have a family history where you have a first-degree relative – like a parent with colon cancer, colorectal cancer or advanced polyps – screening should begin at an earlier age.

If you have multiple family members who are affected – not just first-degree, but second-degree – or if their cancers occurred at a younger age, we may recommend starting screening even earlier and more frequently.

DB: For someone without a family history, how should they approach their risk?

AL: Someone without a family history would know to start or should have their first screening at age 45, but they should pay attention to their symptoms and know the signs and symptoms and then work on prevention – like maintaining healthy weight and staying active.

DB: What are the most common misconceptions you see about colorectal cancer?

AL: There are several. One is that it only affects older adults, which we’ve talked about. We’re seeing more younger cases now. Another is assuming that any bleeding is harmless hemorrhoids.

People sometimes believe that symptoms that improve on their own are not serious or that no family history means no risk. Most early onset colorectal cancer cases are sporadic, meaning there’s no family history.

DB: How have advances in minimally invasive techniques changed outcomes for colorectal cancer patients?

AL: Laparoscopic and robotic surgeries are commonly used so they reduce recovery time, minimize pain and allow our patients to get back more quickly to their daily life.

DB: If there’s one takeaway you’d want every person to remember from this conversation, what would it be?

AL: Making sure that they are listening to their bodies and making sure that they’re not ignoring their symptoms and that they discuss their symptoms with their doctor. For so long, we thought that colon cancer was a disease of older people. The patients I’ve seen who are diagnosed at a younger age, perhaps their rectal bleeding was attributed to hemorrhoids.

There are four big warning signs that can come up years before a diagnosis. So that’s rectal bleeding, abdominal pain, diarrhea and iron deficiency anemia.

Talk to your family. Sometimes knowing your family history, like when you see family members during the holidays. Ask about grandmas and aunts and uncles because that can alert (you) to earlier screening.

At UCLA, we have a very comprehensive program for treating colorectal cancer, from early screening and prevention to advanced surgical and multidisciplinary care. It’s all designed to support patients at every stage.