Warning signs you might have colorectal cancer — and the scary truth about young people who get it

Early-onset colorectal cancer — that is, in people younger than 50 — is on the rise, increasing 1.4% every year and stumping health professionals.

And it’s not so easy to catch early, since so many people who get it seem to otherwise be healthy.

“The most common symptom of colorectal cancer in younger patients is actually no symptom at all. That’s the scary part,” Dr. Parul Shukla, a colon and rectal surgeon with Northwell Health, told The Post.

Shukla said he’s recently operated on multiple patients in their 40s, and some of them appear to be in “great health,” including a vegan woman and a professional baseball player. Plus, data suggests a lag time in diagnoses, meaning by the time young people find out they have it, it’s quite advanced.

But there are signs you can look out for, and the doc has broken down when you shouldn’t worry — and when it’s worth making an appointment.

Your poop habits change

Constipation now and then isn’t a cause for concern, but if you’re normally regular — and then you’re stopped up for weeks or months at a time — that’s not normal and could be a sign that cancer is obstructing your bowels.

“If someone, for years, has regular bowel movements every day, and then all of a sudden they’re struggling to have a bowel movement,” that’s worth investigating, according to Shukla.

“Initially, they might blame it on foods they ate or lack of fiber. But if that is a consistent change from something which you had, then that should not be ignored.”

Very thin stools can also be sign, according to several doctors, as can severe diarrhea.

You’re bleeding

Bloody in the bathroom? Don’t panic — Shukla says that chances are, you just have hemorrhoids. They may be uncomfortable, but they’re not going to kill you.

But if you take steps to combat hemorrhoids — eat more fiber, use a stool softener, stop straining, spend less time on the toilet — and that bleeding persists for weeks, it’s worth checking in with your internist for a rectal exam.

An even surer sign that something might be up down below is that the blood is mixed into your poop, not just on your TP — meaning it’s coming from inside you, rather than just around your butt.

“Blood when you wipe that you see on the toilet paper is likely very distal, very close to the anal area and likely to be hemorrhoids,” explained Shukla. “But if there’s blood dripping into the bowl, if you are seeing a darkish blood coming out in the stool, that means the blood is coming for more proximal.”

Anemia can also be a sign you’re losing blood in the bathroom without realizing it, so if your annual labs show you’re anemic, colorectal cancer could be the cause.

A pain in the —

Pain can signal more advanced cancer, according to the doc.

“If someone has an obstructing type of a tumor and the colon is trying its best to contract and push stools past that, that can create a colicky type of pain,” meaning it comes and goes in waves, Shukla said.

Tension in the colon can also lead to extreme discomfort due to bloating and distension.

Pain after eating can also be a clue, but only if it occurs several hours after your meal. That may mean it’s coming from your small bowl or colon, whereas pain that happens within a couple of hours of eating is likely upper GI, like heartburn, GERD or run-of-the-mill indigestion.

When should you see a doctor?

It’s not uncommon for people to brush symptoms aside for weeks, months or even years, convinced that their issues are no big deal — and at the same time, no one wants to be thought of as a hypochondriac, bringing every last concern to a doctor.

Shukla says that if any of these symptoms last for a few weeks, it’s time to consult with an MD.

Symptoms or no, current guidelines are to start colonoscopies at age 45 and continue to get them every 10 years if the results are normal. For those with a close family history or certain bowel diseases like Crohn’s, the recommendation is earlier.