A single mum says doctors told her that her eight-year-old son was simply 'constipated' - only to later find that he had cancer.
Victoria Stainton, 45, took young Harrison to a GP in November last year after noticing he was struggling to breathe.
She says her doctor informed her that her son's symptoms were likely due to constipation and prescribed him laxatives - but when he was rushed to hospital one day later, a chest X-ray showed his lungs were filled with fluid.
Within an hour the boy was in an operating theatre having a chest drain inserted, where two litres of infected fluid were instantly drained off.
And just days later, they received the horrifying diagnosis of T-Cell Lymphoblastic Lymphoma, a fast-growing cancer that showed as a mass in his thorax.
Recalling her emotions as she was told of his illness, she said to NeedToKnow.co.uk: "There are no words to describe how it feels to hear those words as a diagnosis for your beloved child,"
"When I was told, I just broke down... it felt very surreal like it wasn't really happening - It still feels unreal at times as it's such a long treatment plan.
"I felt broken and scared, how can this be happening to him as he'd always been a good child - I was afraid of losing him as he is my whole world. But you have to pull up your bootstraps and crack on."
Harrison was then transferred to King's College London Hospital, before arriving at St George's in the capital two days later.
A raft of intensive treatment started immediately, including chemotherapy three times a week, twice-daily blood thinner injections to lessen the chance of blood clots, a chest drain removing eight litres of fluid in total, lumbar punctures and a catheter.
Victoria said: "So far it's been a combination of three different types of chemotherapy that need to be done on three consecutive days, to begin with, then two the next week.
"The first six months are very intensive and once through that, it goes into maintenance phases for the remainder of the three years and three months"
Harrison is now predominantly fed through a nasal-gastric feeding tube, but when he is able to eat solid food, while financially struggling Victoria makes sure he is able to eat what he likes - sometimes going without food herself to afford it.
Though she received help from her sister, single mother Susannah Matthews has found it difficult fund transport to the hospital, food and heating bills and was forced to leave her job as a learning assistant to care for her son.
Her immunocompromised son meanwhile can't travel on public transport safely, and with local parking costs now reaching £4 an hour, Victoria is now almost completely dependent on the generosity of others.
One of the dads of Harrison's classmates has since set up a GoFundMe page to help.
Despite his condition, his cancer will not stop Harrison from fighting for others, and as he has raised £830 for the Children's Cancer and Leukaemia group's big play dates by selling pin badges and keyrings to his neighbours.
Victoria reflected: "Harrison is very grateful to everyone because it means that I can be right beside him through every step of his journey.
"Harrison's heroes, our amazing neighbours, are on standby if we need to go to the hospital.
"I'm so proud of him, we take it each day at a time.
She added there have been "so many bumps along the road so far" for the mother and son, but they are still going strong "because we have the support of some amazing people".