Each year more than 5000 gastro-intestinal cancers are diagnosed - and half of those diagnosed will die within five years.
Ms Hamill said when she was finally diagnosed her first fears were that it had spread to other parts of her body because she'd had the symptoms like abdominal pain and blood in her stools for so long beforehand.
She'd only just given birth to her second daughter, Tegan, two months before her diagnosis.
"It was really tough to know this little baby might not know me."
It was in October or November 2014 that Ms Hamill first became aware of blood in her stools but a faecal examination didn't give any answers.
The following February she was referred to a specialist who did a sigmoidoscopy to look in her colon but that only looked at 30cm - her tumour was 40cm up.
Ms Hamill said she was given numerous diagnosis - from fissures to haemorrhoids. When she was finally referred for a colonoscopy she was pregnant so had to postpone it until after Tegan was born.
It was during the colonoscopy the tumour was discovered.
"I remember thinking I've just been told I've got cancer and I've got a 9-week-old."
She said she was told her age and pregnancy could have sped up the cancer and faced an anxious wait for a scan to see whether it had spread.
The cancer had spread to some of her lymph nodes and she had those, and a section of her bowel, removed in surgery followed by 12 months of chemotherapy.
Her message to others is to make sure they listen to their body and push for tests if they think something is wrong.
"The big key is dig deep. Don't just go for what [the doctors] say."
"I was convinced I had cancer but could only go with what the doctors said."
She said thankfully her cancer wasn't a fast growing cancer. She has now finished treatment, but will undergo regular monitoring and scans to make sure it doesn't return.
"My bitterness [with the delay] is there but at the same time I'm grateful I've got my life.
"My girls deserve me to be in their life."
Ms Hamill said she was lucky she did not have many side effects from the chemotherapy and was generally able to go about her day to day life while going through the treatment.
"The support I've had has been amazing. People have come back into my life. A lot of positive things have happened."
She said it was fantastic more people were becoming aware of colorectal cancers.
Ms Hamill said she was happy to talk about her experience in the hope others would know more about bowel cancer and how it could affect younger people.
The #LoveYerGuts Challenge 2017
- Train and commit to do at least 50 gut crunches in five minutes before 5pm on Friday May 5.
- For more information, and to sign up go to www.loveyerguts.co.nz.
- Aimed at raising awareness around gastro-intestinal cancers, collectively the most common form of cancer in New Zealand.
- Funds raised by the #LoveYerGuts Challenge 2017 50 crunches in 5 minutes will help clinical trials and research to increase the chance of survival for those diagnosed with GI (gut) cancer(s).