Two years ago, he was a healthy toddler playing happily at nursery with his little friends.
But one day in early summer 2012, something happened to Bo Cox which left him battling for survival and changed his life forever.
The youngster became infected with potentially-deadly e. coli 0157 and became so ill his mother Lucy feared she would lose him.
He suffered acute kidney failure and was left blind and deaf, had most of his bowel removed and has endured 19 operations.
He receives dialysis four times a week, does not pass urine and is fed through a tube fed straight into his stomach.
The consultant treating him said it was the worst case of e. coli he had seen in a child who had not died from the bug.
Bo, who is now aged three-and-a-half, has spent the past two years as a patient of the Yorkhill Children’s Hospital in Glasgow.
His mum says she not only feels “bitter and sad” about the way her boy’s life has been destroyed by the illness, but also robbed of her motherhood.
Bo was one of four children infected with e. coli at Rose Lodge Nursery at Aboyne in Aberdeenshire in May 2012. Two staff were also infected.
He is the only one not to have recovered.
An official report into the outbreak found the infection had been brought in by a child, possibly after coming into contact with animal faeces – either on the surrounding land or from a contaminated private water supply – and spread through weak infection control practices at the nursery at the time.
Lone parent Ms Cox, 40, said: “Of course there is bitterness and sadness. Bo’s conditions are still life-threatening and, at times, we have been on a knife-edge wondering whether he would survive.
“It has had a really deep effect on us all and it is not something we can get over.
“It won’t ever get better and it will never be back to how it should be.”
A report carried out by NHS Grampian and Aberdeenshire Council in August 2012 demanded improvements to hand washing and some hygiene practices at the nursery.
It was found that staff in the nappy room may not have been cleaning their hands properly, given the hot temperature of the water.
Staff were immediately ordered to stop using a communal bowl in the baby room to wash their hands.
In July last year, the Care Inspectorate said the nursery had addressed all infection control matters and rated the service “good” in all areas.
But Ms Cox claimed there had been a lack of recognition of the consequences of the outbreak.
Ms Cox said: “There has been no mention since as to how extreme Bo’s illness has been. When the report was written in 2012 he was just coming out of intensive care, but things continued to get worse.
“I feel that Bo’s illness has just been allowed to happen.
“We feel so insignificant or that it doesn’t matter, or that people think ‘it’s not my child so it is not my problem’.”
Ms Cox now lives permanently in Glasgow given Bo’s medical treatment at Yorkhill.
Her mother has also left Aberdeenshire to be close to her daughter and grandson.
Ms Cox, a former office manager, now cares full-time for Bo.
She said she felt “totally isolated” in a city she does not know.
She said: “People say you have to find the hope but it is incredibly hard not to think that it just shouldn’t be like this, that this didn’t need to happen’.
“I feel absolutely robbed, for him and for me. I am robbed of all the motherly things you should do, like feeding him a home cooked meal and taking him swimming, the things we did before.
“Just for him to see what I look like and for him to see what he looks like.”
Bo was discharged as an inpatient from Yorkhill in January and can now live at home, with the help of night carers and respite staff from the Robin House Hospice at Loch Lomond. He is fed by tubes continuously as he sleeps.
The next possible step is to prepare Bo for a kidney transplant, but the very poor state of his gut means he would not yet be able to absorb the medication to help his body accept the organ.
After all he has been through, Ms Cox is worried about him having more major surgery.
However, a kidney transplant is the only long-term solution
She said: “The future, medically speaking, is really quite frightening.
“The suffering he went through due to the initial infection and following an operation on his bowel last year is still so raw. How can we see him endure any more?”
A spokesman for the Care Inspectorate said the family had suffered a “tragedy”.
He said: “No family should have to go through a tragedy like this. It highlights, in a heartbreaking way, the need for every agency to be vigilant and proactive in doing everything possible to prevent infection.
“We regularly inspect all nurseries, most unannounced, and require each to have an up-to-date infection control policy which staff and parents understand, and which meets the latest standards.
“NHS Grampian carried out a very important review of the e. coli outbreak at Roselodge. Following that, we have increased our resources to look in-depth at how well infection prevention and control is carried out at every nursery in Scotland.
“That started in April and is an additional, focused part of our inspection programme.
“Every child is entitled to safe, compassionate care and we have recently issued new guidance on nappy changing in nurseries.
“We urge parents and staff to be vigilant.”
Lawyers for Ms Cox are working to mount a legal action against the nursery.
Julie Grant, owner of Rose Lodge Nursery, declined to comment last night.