I got stage 3 colon cancer at 33... the unglamorous symptom you shouldn't be too embarrassed to get checked

A California mother has revealed the 'unglamorous' colon cancer symptom her doctors ignored for years.

Shortly after giving birth to her oldest son in 2015, Marisa Peters noticed a small amount of blood on her toilet paper.

Doctors immediately blamed the blood on childbirth, as the straining can lead to hemorrhoids, and assumed the then 33-year-old had 'different expectations' of the physical complications of giving birth.

Over the next five years, the symptoms became increasingly more concerning.

Blood now filled the toilet bowl after a bowel movement and her stool became smaller and 'shaggy.' She also developed anemia - a lack of healthy red blood cells - and suffered episodes of sudden urgency to rush to the bathroom.

Peters gave birth to two more sons in that five-year timeframe, rapidly losing large amounts of blood during her youngest son's birth. Soon after, the blood loss caused Peters to see a gastroenterologist that became 'shocked and concerned' after hearing her symptoms. The doctor referred her for a stool test.

The test came back positive for colon cancer markers, and a colonoscopy soon revealed a pomegranate-sized tumor in her rectum.

After a series of further scans, Peters, then 39, was diagnosed with stage three rectal cancer in summer 2021.

Peters, now 43 and a nonprofit founder, told TODAY.com: 'Life immediately turned upside down overnight as it does for anybody when they get life [changing] news like that.

'Cancer had been the furthest thing from my mind.'

Peters' cancer is considered early-onset, referring to cases in people under 50, which are on the rise in the US.

The latest data shows early-onset colon cancer diagnoses in the US are expected to rise by 90 percent in people 20 to 34 years old between 2010 and 2030.

In teens, rates have surged 500 percent since the early 2000s.

From 1999 to 2018, the rate of colon cancer in people under 50 increased from 8.6 cases per 100,000 to 13 cases per 100,000 people.

Lifestyle factors like diets of ultra-processed foods, lack of exercise and being sedentary have all been blamed, along with environmental exposures.

Most recently, a study from the University of California San Diego suggested childhood exposure to toxins produced by E. coli may set the stage for colon cancer later in life.

Common symptoms include blood in the stool and abdominal pain, which are most often caused by more benign conditions like hemorrhoids, leading many doctors to not suspect colon cancer at first - such as in Peters' case.

Doctors now believe her sudden bowel urgency came from the tumor sitting at the bottom of her rectum, the last part of the large intestine that connects the colon to the anus.

Peters underwent 28 rounds of radiation with oral chemotherapy every weekday for five and a half weeks. She then had a seven-hour surgery to remove the mass and reconstruct her rectum, followed by another six rounds of chemotherapy.

She said: 'That is when I feel like the real battle started because you realize what has gone on in your life.

'Thankfully, gratefully, miraculously I had a complete response to treatment.'

Peters is now cancer free and focusing on advocacy work.

Soon after completing treatments, she started the nonprofit Be Seen, which aims to 'eradicate death by young onset colorectal cancer' through three pillars: awareness, access and research and taking action, such as with a stool test or colonoscopy.

Peters said: 'I’m never going to stop talking about this. If I can help humanize and make this more realistic by sharing my own story, as improper or unglamorous... as it might be, I am never going to stop sharing that.'