Fitness coach discovers colon cancer after years of IBS misdiagnosis

Danni Duncan, a 40-year-old fitness and nutrition coach from the Gold Coast, has dealt with IBS since childhood and later improved her health through whole-food diets and marathon training. In her late 30s, after giving birth to her fourth child, she experienced renewed constipation, bloating and extreme fatigue, which she attributed to IBS. A blood test in April 2025 showed a hemoglobin level of 70 g/L, leading doctors to schedule a colonoscopy that revealed a tumor, resulting in a stage 2B colon cancer diagnosis.

She had a right hemicolectomy with 17 lymph nodes removed and completed four cycles of oxaliplatin-based chemotherapy, coping with severe fatigue, nausea and the inability to breastfeed. By November 2025, scans showed no remaining cancer, and she is now preparing for the New York City Marathon, running on behalf of the Jodi Lee Foundation and urging younger adults to seek medical evaluation for atypical bowel symptoms.