The shock findings have prompted calls from health experts for younger Australians to start being screened for the deadly disease.
1 in 10 bowel cancers are now detected in people under the age of 50 and 103 Australians die from the disease each year, making it Australia's second deadliest cancer.
Bowel Cancer Australia CEO Julien Wiggins told Sunrise that the rise is likely linked to diet and lifestyle.
"There was a rise in the number of younger people diagnosed, compared to those over 50 where rates were either declining of staying the same," he said.
"Research indicates it could be related to excess body weight, red meat consumption, alcohol consumption, smoking, lack of exercise or lack of dietary fiber intake."
Wiggins encourages anyone with concerns or symptoms to see their GP as soon as possible.
Blood in the stool
Change in bathroom habits
Change in stool appearance
Unexplained weight loss or anaemia
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