Like many proud parents, Pam Olson of Woodbury had a good cry watching her daughter Bridget graduate from college recently.

Unlike many parents, however, her tears carried added weight. She once doubted she’d see this happy day.

At 39, Olson was found to have colon cancer. Within weeks, she’d had surgery to remove part of her colon and had begun six months of chemotherapy.

“You just sort of think, ‘What am I going to miss?’ ” said Olson, now 52 and office coordinator at Bailey Elementary School in Woodbury. Her two daughters were in grade school at the time.

“You sort of start planning, right? Like you’re not going to be around.”

Today, Olson is cancer-free and about to celebrate her 25th wedding anniversary with husband Dave. She’s also free of filters when talking about the disease we don’t want to talk about.

“Just remember, it’s important to check your poop,” she said.

Getting a colonoscopy (an exam to find abnormalities in the colon) remains her “least favorite thing to do, but it’s not as bad as people make it out to be.”

Olson’s message to look down, if you will, carries great urgency, coming on the heels of news from the American Cancer Society. A couple of weeks ago, the organization changed its guidelines to recommend that colorectal cancer screening begin at age 45 for people at average risk, instead of 50. Those with a family history were told to be screened even earlier.

While 90 percent of colorectal cases still are found in people over 50 — which is the reason colonoscopies previously were recommended to begin then — studies show a 50 percent rise in colorectal rates among adults under 50 from 1994 to 2014. More alarming, colorectal cancers are being found in people as young as their 20s and 30s. This is no longer an “older person’s” disease.

While colon cancer remains the second-leading cause of cancer deaths among U.S. adults, stakeholders know that getting people to take heed is a tough sell. People are embarrassed to discuss their bowel habits, said Matt Flory, Minnesota health systems manager for the American Cancer Society.

“With breast cancer, there’s not so much stigma,” he said. “Colon cancer has an extra level of discomfort.”

Tim Church agreed. “People just think it’s an icky topic,” said Church, a professor at the University of Minnesota’s Public Health School. Only two-thirds of people 50 and older get a colonoscopy, he said, despite aggressive outreach by doctors hoping for an 80 percent participation rate by the end of 2018.

People, it seems, would rather have oral surgery than undergo the “prep” required to clean out their systems. Or they don’t want co-workers to know why they took a day off. Or they’re afraid of what might be found during the procedure.

As the daughter of a mother who is a 22-year colon cancer survivor, and hence considered higher risk myself, let me tackle those worries for you:

• The prep for a colonoscopy is unpleasant but tolerable, and it’s getting easier every year. Plus, you typically have to do it only once every 10 years.

• Your co-workers should be getting a colonoscopy, too, so make it a work outing.

• The comforting thing about the screening is that if polyps are found, they can be removed during the procedure, which prevents up to 90 percent of colorectal cancer.

In other words, stop stalling. If your health insurance covers colonoscopy, be grateful and see your doctor. If you don’t have coverage, talk to your doctor about other screening options, such as flexible sigmoidoscopy, virtual colonoscopy and stool-based tests. (All three, however, do require a traditional colonoscopy if abnormal results are seen.)

Causes remain perplexing

Reasons for the increase in colorectal cancer remain frustratingly murky, but a few culprits appear on many lists. Obesity. Lack of exercise. Processed foods. Smoking.

“We don’t know what causes cancer. That’s the problem,” said Dr. Casandra Anderson, a surgical oncologist with the Virginia Piper Cancer Institute. “We’re seeing increases in breast cancer in younger ages, too. Is it environmental? Genes? They both play a role.”

Anderson said diet likely has an impact, including processed foods and red meat, “but it’s hard to say cause and effect.”

Having recently operated on a 30-year-old with colon cancer, it is not hard for Anderson to say, “Get your screening — don’t wait. It happens in younger people.” She added, “Colon cancer can be prevented.”

Flory also remains perplexed about the causes. “Adults born in 1990 have twice the risk of colon cancer and four times the risk of rectal cancer compared to those born in 1950, and we don’t really know why,” he said. “It might be diet. It might be obesity.” Environmental factors might play a role, too, he said.

“What we can say is, it’s probably not genetics or family history because people’s DNA doesn’t change that much in that short a period.”

While a colonoscopy is still considered the “gold standard” among some doctors, Flory noted that the best test “is the test that gets done. We would absolutely suggest that people go to our website, and talk to their physicians.”

Olson vividly remembers the days leading up to her diagnosis. She was “a little concerned” about changes in her bowels; she’d have diarrhea, then constipation. “Just a variety of things,” she said. “I’d wake up during the night with stomachaches.”

She thought she had irritable bowel syndrome. When she discovered blood in her stool, her doctor ordered a colonoscopy.

The cancer was in the wall of her colon but hadn’t spread. She and Dave sat down their girls, Gretchen, now 18, and Bridget, now 22, “and told them I was sick. I don’t know if we used the word cancer. We told them we don’t know what’s going to happen but that I would have to have surgery. We didn’t want to tell them too much because we didn’t want to scare them.”

Family and friends pitched in, cooking, cleaning and driving the girls to and from their activities.

Thirteen years later, Olson has gone from annual colonoscopies to one every three years. Her daughters will begin getting the test in their 30s. The family remains active with the American Cancer Society, organizing the annual ACS Relay for Life in south Washington County.

Bridget graduated from St. Olaf College with a degree in psychology and is considering graduate school. Gretchen just completed her first year at St. Olaf. Their mom is around to share every moment, big and small.

“I remember coming out of surgery — you’re groggy and you feel awful and everyone is trying to keep the mood light,” Olson said. That’s when she uttered those first words that “it’s important to check your poop,” which cracked up everyone in the room.

“But, obviously that’s my story. It’s important to be aware of your body, and when your body is telling you something that it hasn’t been telling you before.”