'Fit and healthy' mum diagnosed with bowel cancer explains common misconception about illness

The rapid rise in cases of colorectal cancer is hugely concerning and yet it can still come with a significant amount of misconception.

Bowel cancer has long been thought of as something which affects the older generations but it is now the fourth most common cancer in the UK and is increasingly affecting people under the age of 50.

Although the exact reasons for the growth haven't been identified, the increase in ultra-processed foods has been identified as a potential reason why, with more and more people getting diagnosed every day.

A huge issue with the illness is that doctors can often misdiagnose bowel cancer as stomach issues such as IBS, which can then lead to more fatalities as bowel cancer tumours are allowed to grow unchecked.

Danni Duncan, an Australian mum-of-three, has pointed out that both of these misconceptions led to her bowel cancer diagnosis when she was just 39.

Danni was told she couldn't breast feed her daughter after the chemotherapy (Instagram/@danni.duncan_)

“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 explained.

“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.”

She was training for a marathon having given birth just 12 weeks before but she decided to get herself more thoroughly checked after feeling dizzy at the gym.

A colonoscopy on 15 May 2025 revealed that she had a 2.7cm malignant tumour in her bowel, which was later removed alongside three months of chemotherapy.

Although she is now thankfully cancer free, the mum has pointed out that she had none of the usual signs of someone who might be considered more likely to suffer from bowel cancer.

She was young, very healthy in terms of diet and exercise and didn't smoke, which was perhaps why doctors weren't too concerned before her colonoscopy, with some even suggesting that it might have been perimenopause.

Danni said in a social media post: "The last four years I have eaten 80-90 percent whole foods, we use non-toxic products at home, I don't drink much alcohol, exercise every day and eat a high fibre diet."

Danni was training for a marathon when she got her diagnosis (Instagram/@danni.duncan_)

She and her surgeon both certainly seem to think that it was harmful foods as a child that led to her cancer diagnosis however, as she added: "When I was in the surgeon's appointment on Monday, he said something so interesting.

"He said, 'This is what's happened - chemicals in your foods, carcinogens through red meat, burnt, barbecued, bacon, ham - they are environmental factors which we got exposed to in the 90s and we didn't know the long-term effects until now'."

Red meat is widely considered to be a carcinogen and a potential factor in bowel cancer cases, which are growing at an alarming rate while other cancers tend to be on more of a downward trend.

Danni's case is yet another example of why it is so important to get tested if you do show any of the potential symptoms or red flags associated with bowel cancer, even if you're young and healthy, because early diagnosis is crucial to your eventual survival.

If you’ve been affected by any of these issues and want to speak to someone in confidence, contact Macmillan’s Cancer Support Line on 0808 808 00 00, 8am–8pm seven days a week.