Researchers at the University of Otago Faculty of Medicine and Bowel Cancer NZ have examined the experiences of 353 New Zealanders diagnosed with bowel cancer before turning 50, uncovering delays and barriers to testing.

Half of those surveyed waited more than six months between first symptoms and diagnosis. Around 20% attended four or more medical appointments before receiving a referral for testing, and nearly 32% were misdiagnosed. 7.1% had colonoscopy referrals initially refused.

Amelia Noyes was denied a colonoscopy at age 21 despite presenting with symptoms and a family history that included her mother's death from bowel cancer at 56 and her maternal grandmother's death from the disease in her 80s. Five years later, at 26, she was diagnosed with stage 3 rectal cancer. Doctors discovered a seven-centimetre tumour and 12 pre-cancerous polyps.

"Blood in the stool all the time, and jumping between diarrhoea and constipation," Noyes said of her symptoms. Doctors initially suggested haemorrhoids or anal fissures and recommended she eat more fibre or lose weight.

Radiation treatment has left Noyes requiring a surrogate to carry any future pregnancy. "I've always been a family person, and I've always wanted to have a big family. To have that sort of dream of being a young girl, always wanting to grow up and marry someone and become a mother, that dream's kind of been cut short for me."

The study, published in the New Zealand Medical Journal, found rectal bleeding was the most frequent symptom prompting medical visits, affecting almost half of respondents. Abdominal pain and changes in bowel habits were also common. Misdiagnoses included IBS, food intolerances and ulcerative colitis.

Around 350 New Zealanders under 50 receive bowel cancer diagnoses each year. Bowel Cancer NZ chief executive Peter Huskinson said "bowel cancer that happens in your 20s, 30s, or 40s, is growing faster in New Zealand than any other country in the world".

One in 10 colorectal cancer cases worldwide now occur in people under 50. Cases among younger people have increased globally over the past two decades while stabilising or falling in older groups. A third of early-onset cases present at late stage when the disease is incurable.

The survey found only 12.8% of respondents received information about fertility and sexual side effects appropriate to younger adults, and 7.6% were offered cultural support. Almost 60% required extended leave from work or study, and nearly half experienced financial hardship from treatment costs, lost income or additional family expenses.

Huskinson said financial pain was part of the process for young patients.