June is Bowel Cancer Awareness Month, and one Australian mum is using her own diagnosis to make sure other parents catch the warning signs she missed.
In 2024, Danni Duncan was a happy mum of three working as a nutrition and fitness coach specialising in women’s health. She had no idea that during her fourth pregnancy, something far more serious was developing alongside her growing baby.
“During that pregnancy my iron was very low, so they sent me for an iron infusion. My levels increased at first, and everyone thought it was fine, but then my iron levels plummeted again,” Danni said.
Looking back, she says there were subtle signs that something was wrong well before her pregnancy.
“About two years before I got diagnosed, I did start taking Metamucil every night before bed because I found I wasn’t going to the toilet regularly,” she said. “I would alternate between constipation and diarrhoea but I was diagnosed with IBS years ago, so I assumed that’s what it was. Irregular bowel movements were ‘normal’ for me but looking back I see that as a red flag.”
Like many women, her low iron and fatigue were blamed on pregnancy and postpartum, so she carried on as normal and started training for a marathon at 12 weeks postpartum. Over the next month she had dizzy spells and couldn’t finish a set of weights at the gym, but Danni put it down to anxiety. One day she almost collapsed in her kitchen, and her husband insisted she go to the GP.
“I was severely anaemic. My iron was 1, my haemoglobin was 70, and the doctor said, ‘Danni you should be bleeding out in front of me and you’re not. We’ve got to find out where this bleeding is coming from’,” she said.
On 15 May 2025, a colonoscopy and gastroscopy revealed her worst nightmare.
“I woke up from the colonoscopy and gastroscopy and the doctor says, ‘I’m so sorry Danni but I’ve seen something I didn’t want to see. You’ve got a 2.7cm malignant tumour in your bowel. You have bowel cancer’,” she said.
Completely blindsided, Danni had expected a diagnosis of coeliac disease or an ulcer. On 28 May she had surgery to remove 25cm of her bowel, followed by three months of chemotherapy.
“I was told I wouldn’t be able to breastfeed my baby, and that was probably the hardest part. I breastfed London for the last time when she was 9 months old. The side effects from the chemo were atrocious. I suffered with extreme cold sensitivity and nausea but still tried to exercise throughout my treatment,” she said.
Danni finished chemotherapy in September 2025 and completed a HYROX event three months later with her husband Chris. She’s now training for the New York City Marathon in November 2026, raising money for the Jodi Lee Foundation, of which she’s an ambassador. The race will mark 12 months since Danni was declared cancer free.
In the meantime, she’s using her platform as a nutrition and fitness coach, and her app FIT by Danni Duncan, to raise awareness of the early signs and symptoms of bowel cancer.
“Getting bowel cancer was this extra thing I needed to really instil my purpose of what I am meant to do,” she said. “People say, ‘oh you’re fearmongering’ and I say, yeah be scared. Because what you feed yourself and your life choices now will impact your outcome.”
Key facts about bowel cancer in Australia
- One in eight Australians diagnosed with bowel cancer are under the age of 50.
- Rates of early onset bowel cancer (diagnosed before age 50) have been rising in Australia and globally since the early 2000s.
- Australia has the highest rate of early onset bowel cancer among 50 countries analysed globally.
- The risk of being diagnosed with bowel cancer before age 40 has more than doubled since the year 2000.
- Bowel cancer is the deadliest cancer for Australians aged 25 to 54.
- Bowel cancer rates are two to three times higher among Australians born in the 1990s than those born in the 1950s.
For more information on bowel cancer, visit Bowel Cancer Australia
To support Danni’s New York City Marathon fundraiser, visit the Jodi Lee Foundation
For more on Danni’s story, visit danniduncan.com.au
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