A baby who was allegedly misdiagnosed at a NSW hospital had to wait four hours for an ambulance because paramedics were having lunch, an inquest has heard.

Six-month-old Kyran Day was admitted to Shoalhaven Hospital on the state's south coast in ­October 2013 and died three days later, The Daily Telegraph reports.

Doctors initially believed the infant was suffering from gastroenteritis but 20 hours after he first saw a doctor they found the boy actually had a bowel obstruction.

He was subsequently rushed to the Sydney Children's Hospital for specialist surgery but had already suffered cardiac arrests.

After successful bowel surgery, Kyran was placed on life support but it was switched off two days later on October 22.

The official cause of death was listed as starvation of oxygen to the brain.

The inquest is examining the role of the Shoalhaven Hospital and its staff, the Newborn Emergency Transport Service and NSW Ambulance.

Some of the issues to be scrutinised will be why a request for a helicopter was rejected, the handover from the ­hospital to paramedics and why a nurse did not escort the ambulance.

After the decision was made to transport Kyran by ambulance instead of by helicopter, another four hours passed before the 150km trip commenced.

The inquest heard the first ambulance dispatched was called off so its crew could have lunch.

The second ambulance was delayed because they already had a patient and also needed to eat before the drive to Sydney.

But the crew never made it to Sydney because an hour into the journey the infant stopped breathing properly and the ambulance diverted to Shellharbour Hospital so he could be resuscitated.

Four hours after arriving at the hospital he was taken to Sydney by helicopter.

Kyran's mother, Naomi Daym said the inquest had been "hell".