Since a 2017 study sounded the alarm, I've been telling younger people that they're at an increased risk for colorectal cancer. In fact, if you were born between 1981 and 1996, you have twice the risk of people born in 1950.

Today, fully one-third of colorectal cancer patients are under 55. And if you're 55 or younger when you're diagnosed, you're 60% more likely to have more advanced disease.

That's why it's important to know the symptoms of increased risk for early-onset colorectal cancer.

A study published in the Journal of the National Cancer Institute reveals many younger people experience abdominal pain, rectal bleeding, persistent diarrhea, and/or iron deficiency anemia three months to two years before diagnosis.

Having any one of those symptoms almost doubles the risk in people under 50. Having two symptoms boosts the risk 350% (that's 3.5 times the risk). And having three or more of the symptoms at that age increases the risk 650%.

Starting at age 45, everyone should be screened for colon cancer. A well-performed colonoscopy is 98% accurate and allows for removal of precancerous polyps.

The at-home tests range from 92% accuracy for the stool DNA test (Cologuard) for people at average risk to 75% to 79% for FIT (fecal immunochemical test). And they're not good at detecting polyps — so important for preventing cancer.

If you're 45 or older and haven't had a colonoscopy, schedule one, and then ask if and when at-home tests are safe for you.