The family of a woman who died at Huddersfield Royal Infirmary launched a protest on the anniversary of her death.
Holmfirth’s John Moore and his son Theo tied a banner to hospital fencing that said: “This hospital killed Susan” and handed out leaflets to passers-by.
Susan Brook, 54, died on August 5, 2012 weighing just four stone after months of health problems.
The mother of three was rushed to the infirmary on August 2 that year but died from “catastrophic” bowel failure three days later.
Hospital chiefs admitted some shortcomings.
But after two years of looking for answers Mr Moore said officials at Calderdale and Huddersfield NHS Trust had not been able to answer his questions and so he was calling for a public inquiry.
He said: “They’ve put themselves in a nutshell and I want to crack that nut.
“I’ve gone as far as I can looking for answers and I’ve got none, but I’m still trying.”
Mr Moore said hospital security had tried to stop him from installing his banner but left him alone after he told them it was his right under law.
Director of Nursing at the hospital trust, Julie Dawes, said: “We would like to resend our condolences to Mr Moore and his family on the anniversary of their sad loss.”