The 66-year-old said his cancer went undiagnosed for more than four months.
�I was feeling very sick and constipated around Christmas time, but I thought it was maybe acid in my stomach,� Mr Zirino said.
�I got some medicine, but the cramps just wouldn�t go away.
�Eventually I went to have an X-ray and the doctor found I had a blockage, but she said she would let me know if it was anything serious.
�It was not until I had a colonoscopy in April that I found out the truth.�
Royal Perth Hospital colorectal surgeon Mary Theophilus said Mr Zirino �sailed through� his surgery last month.
�We are getting much better at doing the surgery than 20 years ago,� she said.
�In the past, Michael would have got a massive cut from top to bottom, but instead he only had a very small one with keyhole surgery. He was home in five days.�
Dr Theophilus said the most important message to take away from Mr Zirino�s story was to have regular colonoscopies.
�Michael was scared to have a colonoscopy two years ago but if he had done, we might have caught it at a pre-cancerous stage and would not have needed to operate,� she said.
�With bowel cancer you feel nothing until it�s advanced to a certain stage.
�We have the National Bowel Cancer Screening program now and a lot of people don�t take it up.
�The longer you leave it, the higher the risk of having a stoma, surgery or major issue later on.�
Bowel cancer causes the second-highest number of cancer deaths in Australia. Visit www.bowelcanceraustralia.org/screening