The company said it is investigating all the circumstances surrounding the incident on the route 40 Tralee to Cork bus, to ensure it does not happen again.

“We apologise if any undue distress was caused in this situation, and we will be in contact with the customer directly,” a company spokesperson said.

Bus Eireann has apologised for the treatment of an elderly man who was asked to get off a bus after vomiting, says it's investigating #Cork — Eoin English (@EoinBearla) September 12, 2014

Dan Joe Lucey, who lives in Ballyvourney, Co Cork, and who is known across the county for selling eggs door-to-door, boarded the bus in Ballyvourney early on Wednesday morning.

Tralee woman Miriam Moriarty Owens, who was on board, said: “He looked frail and unwell. It was his colour which struck me most. He was the colour of death.”

Mr Lucey sat two rows behind her and within minutes, became violently ill, vomiting several times.

There were about eight passengers on board and some put newspaper on the floor. Mr Lucey continued vomiting and when the bus arrived in Macroom, Ms Moriarty Owens said several passengers asked that he be removed from the bus.

She asked him if she could call anyone for him, but he said he had no-one.

The bus driver then insisted he get off the vehicle, before driving off, leaving Mr Lucey at the bus stop.

“He could barely stand. He had vomit all over his clothes. He could have been seriously ill; we just didn’t know. It was inhumane treatment. He was treated like a bag of rubbish,” Ms Moriarty Owens said.

“If I was on a plane and getting sick, would I have been thrown out the window? I was so upset by what happened. My big regret is that I should have got off the bus.”

She raised her concerns on social media, complained to Bus Éireann, and contacted Macroom gardaí to express her concern for his welfare. They visited Mr Lucey yesterday and established he had been suffering from a severe bout of food poisoning, and is recovering.

Bus Éireann said it is investigating, to find “a remedy that prevents an instance like this occurring again”.

A spokesperson said: “The welfare and safety of customers on our services is of paramount importance.”