The race is on to boost the number of Australians taking bowel cancer detection tests with participation dropping during the pandemic and natural disasters.

Just 40.9 per cent of eligible people did the test in 2020-21, down from 43.9 per cent the year before.

The black summer bushfires in that time reduced participation by 27 per cent, according to research by the Cancer Council Victoria.

It showed devastating flooding events across the nation from 2020 to 2022 also led to a 23 per cent slump in returned tests.

Federal Health Minister Mark Butler has revealed a $10.8 million boost to Cancer Council Australia so it can roll out a "Get2It" campaign in several languages.

Some 6.1 million people aged 50-74 received early detection tests in the mail in 2020-21 but just 2.49 million were returned, according to the latest national bowel cancer screening program report.

Almost 77,000 received a positive result which required further investigation however colonoscopy wait times increased in every state and territory.

Depending on where they live, some Tasmanians had to wait 235 days while Western Australians waited 119 days.

Just one in six people were seen within the suggested 30-day time frame and guidelines state waiting more than 120 days for a colonoscopy is associated with a poorer outcome.

It's believed nine in ten cases detected early can be treated successfully however the benefits are lost if that is not followed up with a colonoscopy quickly, according to Bowel Cancer Australia chief executive Julien Wiggins.

"We need to ensure participants are not left waiting for long periods after receiving a positive screening result, not knowing if cancer is present," Mr Wiggins said.

More than 15,600 Australians are diagnosed with bowel cancer each year and one in ten are under the age of 50, meaning they are not eligible for the national screening program.

It is the second deadliest cancer behind lung cancer, with 5300 patients dying each year.