A running enthusiast who tragically lost his 14-month-old boy in 2012 is set to take on a marathon challenge on what would have been his son's 10th birthday.

Alex Belsom's son, James Elliss-Belsom was just over a year old when he suddenly became unwell at his home in Ipswich.

Ipswich Star: From left to right: Robin Belsom, Alistair Belsom, Alex Belsom and Natasha Dunnage who will be running a super marathon to raise money for the Colchester and Ipswich Hospital Charity.From left to right: Robin Belsom, Alistair Belsom, Alex Belsom and Natasha Dunnage who will be running a super marathon to raise money for the Colchester and Ipswich Hospital Charity. (Image: The Belsom Family)

He was taken to Ipswich Hospital, but the family were told to give him pain relief and were sent home.

However, James' situation worsened and he was later admitted after being diagnosed with necrotising fasciitis.

The family were rushed to Addenbrookes Hospital in Cambridge by ambulance but sadly, James could not be saved.

Just a week later, Alex's partner Sophie gave birth to their second child.

New Year's Day will mark what would have been James' 10th birthday and Alex, flanked by his brother Alistair, 36, and sister Natasha, 34, will run a 40-mile "super marathon" to raise money for the Colchester and Ipswich Hospitals Charity.

His dad, Robin, will also run 10 miles for the cause.

"After James passed away, we had a lot of heartache and I've never really spoken about it," Alex said.

"I was devastated.

Ipswich Star: James Elliss-Belsom sat on the shoulders of his dad, Alex Belsom who will run a super marathon for charity.James Elliss-Belsom sat on the shoulders of his dad, Alex Belsom who will run a super marathon for charity. (Image: The Belsom Family)

"Things just accelerated really quickly at the hospital.

"We were there in the morning and by the evening things had got a lot worse so we were taken up to Cambridge in an ambulance and he passed away in the ICU in Addenbrookes - and then 10 days later his sister was born.

"I knew that New Year's Day was coming around and I dreamt that I would run 40 miles on his birthday.

"I don't know why I want to do it, I think it's a mental thing.

"It's almost a way of me putting myself through some pain to make myself closer to him.

"It felt like a way of accepting what happened and raising some money to do a good deed really."

You can donate to Alex's cause here

In total, the family will run a combined 130 miles and will aim to complete the final part of the route, which will end at the cemetery where James is buried, together.

Ipswich Star: James Elliss-Belsom sadly died after being rushed to Addenbrookes Hospital in Cambridge in 2012.James Elliss-Belsom sadly died after being rushed to Addenbrookes Hospital in Cambridge in 2012. (Image: The Belsom Family)

They have already raised more than £1,400 and are hoping to reach a total of £2,500 by the new year.

All three siblings have run marathons before, however the distance is far greater than any of them have previously managed.

Alex, 32, said he is glad of the support from his family who, at the time of James' death, "kept him going".

"It was family that got me through it when I lost James," he added.

"I hate to think what would have happened if it wasn't for them being there. I have a really good family and they all came around me.

"I can't wait to run together. My sister has the hardest part because she will probably have to run most of it on her own.

"But the plan is to run with each other at the end."

Ipswich Star: Alex Belsom, 32, will run 40 miles alongside his brother and sister on New Year's DayAlex Belsom, 32, will run 40 miles alongside his brother and sister on New Year's Day (Image: The Belsom Family)

Alex's sister, Natasha, described her brother as an "inspiration".

She said: "He is such an inspiration and is such a strong person. He is so positive despite what he has been through.

"I guess I feel that, compared to what he has been through, this run is far easier.

"For him to be as strong as he's been I feel like I couldn't do any less.

"It's right to do something to support children because of James' story.

"We wanted to do something to make a difference for families who are going through similar circumstances."

Donations to Alex's cause can be made here.