I got rectal cancer at 47 — I was fit and healthy except for this one symptom (2025)

Marcus Wendling toughed out a half Ironman — a grueling triathlon consisting of a 1.2-mile swim, a 56-mile bike ride and a 13.1-mile run — in just under six hours.

He thought the May 2023 race was his greatest physical challenge — until he was diagnosed with Stage 3 rectal cancer months later at the age of 47.

“I eat a healthy diet. I exercise six days a week. I always have been on top of my health,” Wendling, who lives in Dayton, Ohio, told The Post. “So up until that time, you feel like you have this sense of invincibility.”

Rectal cancer is becoming more common in people under 50 — though doctors aren’t exactly sure why. Wendling hopes sharing his story encourages others to seek medical help if something seems amiss, so they don’t face an excruciating battle.

The father of three, who owns a small manufacturing company, was startled to see blood in his stool in the early months of 2023. He had no other symptoms.

“I’ve never had a medical issue or a diagnosis,” said Wendling, now 48.

“I went for a full physical, and everything — all the blood work and numbers — turned out great,” he added, “but I told that doctor in Dayton, I said, ‘Hey, I need to get a colonoscopy. I’m seeing blood at times in my stool,’ and that’s what led to the colonoscopy in November of 2023.”

That was Wendling’s first colonoscopy. Just as he turned 45 in 2021, the US Preventive Services Task Force lowered the recommended age to start screening from 50 to 45 for adults at average risk.

Wendling doesn’t have a family history of colorectal cancer and wasn’t experiencing symptoms, so he saw no reason to have one at the time.

When his doctor ordered one in the fall of 2023, he was understandably nervous.

A biopsy revealed a benign polyp in his colon. A large polyp was removed from his lower rectum — it tested positive for cancer.

“Over the next three months, I went through various tests,” Wendling recalled. “There was an attempt to remove the remaining tissue through a minimally invasive procedure, and that was unsuccessful.”

Due to the location of the tumor, Wendling needed a lower anterior resection.

The five-plus-hour surgery, which involves removing part of the rectum and reattaching the remaining healthy part to the colon, was performed in March 2024 at The Ohio State University Comprehensive Cancer Center – James Cancer Hospital.

Three of the 12 lymph nodes removed during surgery tested positive, so Wendling’s rectal cancer was declared Stage 3.

As if that wasn’t bad enough, he had a rocky hospital stay. He spiked a fever, which turned out to be from a small leak at the surgical site that took four to five weeks to resolve.

“Marcus had a few bumps on the road to recovery, as can happen with treatments, but overall he did great,” Dr. MatthewKalady, Wendling’s surgeon at theOSUCCC-James, told The Post. “He is physically fit and has a great attitude, which definitely helps.”

Wendling underwent 12 weeks of chemotherapy with minimal side effects and got used to life with an ileostomy bag, a pouch that collects waste.

“I was exercising with it, running with it,” Wendling said.

He finally ditched the bag in September 2024 — and things seemed to return to normal around Thanksgiving.

“Marcus was smart in taking ownership of his health and getting his symptoms evaluated early,” Kalady said. “The key to curing colorectal cancer is detecting it and treating it early, before it spreads. His decision to get a colonoscopy early likely saved his life.”

Wendling has to have quarterly scans of his chest and abdominal area and yearly colonoscopies for now, but the news has been good so far.

“I feel like I was very proactive with this,” Wendling said. “So the No. 1 thing I would say is, try to stay on top of your overall health because you never know when you’re going to face something like this.”

He’s even back to training for a half Ironman.

He’ll be at the start line in Florida next month to kick off a new chapter in his journey.

“The No. 1 goal is to finish,” Wendling said. “The No. 2 goal is to beat my time from 2023 — that’s sort of closing the book on last year.”