Ryan Reynolds showed millions of fans the importance of getting a colonoscopy.

The actor said he lost a bet and agreed to record his experience getting the procedure. The 45-year-old posted the video on Instagram.

After the procedure, Reynolds' doctor informed him that a polyp was found.

"This was potentially lifesaving for you," Dr. Jonathan LaPook said. "I'm not kidding. I'm not being overly dramatic."

LaPook said he removed the polyp, which could have led to colon cancer.

"This saves lives pure and simple," he said.

The U.S. Preventive Services Task Force recommends that adults aged 45 to 75 be screened for colorectal cancer.

Colorectal cancer is the fourth leading cause of cancer-related deaths in the U.S., according to the Centers for Disease Control.

The entertainment world is still reeling from the loss of Chadwick Boseman, who died on Friday at the age of 43. Boseman had reportedly been privately fighting colon cancer since 2016, meaning some of his most iconic roles — including those in films like Black Panther, Marshall and 21 Bridges — were likely filmed between grueling chemo treatments.

In the face of such an insurmountable loss, doctors and medical professionals hope that Boseman's cancer battle can shine a light on the dangers of colon cancer in young and middle-aged people and encourage them to undergo annual screenings.

According to the Centers for Disease Control and Prevention, colon cancer is currently the second-leading cause of cancer deaths in the United States. In 2017, more than 50,000 people died of the disease.

And while colon cancer is most common in people 50 years and older, researchers say cases among younger people are on the rise.

Researchers say that doctors have been able to catch the disease early in older people because of a push for increased screenings, but they're still at a loss for why the disease is increasing in young people — though rising rates of obesity may be a factor.

Furthermore, Boseman's death is highlighting the rates of colon cancer in Black Americans — according to the American Cancer Society, Black people have the highest rates of colorectal cancer of any racial or ethnic group in the U.S.

But what are the symptoms of the disease?

According to the American Cancer Society, colon cancer typically presents with:

• Change of bowel habits
• Feeling the need to go, but not feeling relief after
• Rectal bleeding with bright red blood
• Blood in the stool making it look dark brown or black
• Cramping or abdominal pain
• Weakness or fatigue
• Unintended weight loss

While those symptoms don't necessarily guarantee a cancer diagnosis, the American Cancer Society recommends anyone with those symptoms visit a doctor.

The Mayo Clinic adds that the following could leave a person with a higher risk of colon cancer:

• Old age (50 and above)
• Race factors (Black men are 24% more likely to develop colon cancer than white men, and Black men die 47% more likely to die of the disease than white men)
• History of colon tumors or polyps
• Inflammatory intestinal conditions, like ulcerative colitis or Chron's disease
• Family history of colon cancer
• A diet low in fiber and high in fat
• Sedentary lifestyle
• Diabetes
• Obesity
• Smoking/alcohol use
• History of radiation treatments in the abdomen