Bradley Lowery is set to head back to hospital this week for further checks.
The five-year-old from Blackhall Colliery is due to under go blood tests, with his family expecting doctors to decide he needs a feeding tube once again to help keep his strength up.
Mum Gemma posted an update on the Bradley Lowery's Fight Against Neuroblastoma page: "Bradley wasn't too well at the beginning of the weekend so he had some chilled out time watching his favourite films on the couch in a cabin we were kindly offered to stay at.
"Yesterday he went to his grandparents caravan for the night and he had a fab time playing with his friends and doing normal things.
"He said to his Nanna he was pleased he went to the caravan, bless him.
"The week ahead he will be up the hospital to get his bloods checked and unfortunately I think he is going to need his feeding tube put back in because he is not eating enough and is losing weight.
"Bradley will not like this as it is traumatic getting it in however he needs to be nutritionally well to keep his energy levels up to fight the nasties."
A photo of Bradley enjoying a trip to his grandparents' caravan with his friend Kaitlyn was also posted.
Bradley has been undergoing antibody therapy after doctors found his cancer had spread, despite gruelling cancer treatment.
It has been funded thanks to the £700,000-plus raised through donations by supporters.
Next Sunday, Bradley is due to appear as a mascot at England's World Cup 2018 qualifying match against Lithuania at Wembley.