Bailey can have over 200 fits a day due to refractory epilepsy.
The chronic seizures result in him regularly being hospitalised.
His parents decided to fundraise for the treatment themselves as they fear he'll die if he doesn't get it.
They are though continuing their fight for an NHS prescription - it's been legal to prescribe on the health service since November 2018.
Home Secretary Sajid Javid said following the introduction of the new guidelines that specialist doctors in the UK could legally prescribe such products for patients with an "exceptional clinical need." Others forms of cannabis remain illegal.
But doctors here are reluctant to do so because guidelines say there is a lack of evidence to prove it is safe and effective.
Our reporter Emma Grant has been speaking to Bailey's mum Rachel Rankmore. She is one of 17 families across the UK currently being supported by the End Our Pain campaign group trying to get access to medicinal cannabis for their children who have epilepsy or other medical needs. But there are thousands of children with refractory epilepsy in the UK who could benefit from a prescription of medical cannabis.
Our reporter Emma Grant spoke to Rachel a few months ago.
Bailey was first diagnosed with epilepsy at two and a half years of age.
By the time he was Primary school age he was starting to show signs of learning difficulties as a result of the seizures and the side effects of the drugs he was taking
At age seven, Bailey was diagnosed with Lennox-Gastaut Syndrome (a severe form of epilepsy). His mobility started to deteriorate and he needed a wheelchair as he was suffering from drop seizures (when you fall to the ground and shake violently.
When he was 13 his condition got even worse - to the point that he was being hospitalised every week via ambulance - he needed 3 doses of rescue medicine - before he was loaded up with drugs in hospital. His parents were so desperate to help ease his symptoms - they started looking at alternatives - to reduce the horrendous side effects he'd been suffering from the drugs he was taking.
They decided to fund the purchase of CBD oil which has helped ease his symptoms over the past 4 years - but Bailey still has epileptic fits daily because it hasn't got the THC ingredient.
THC is in full extract cannabis medicine which was made legal for prescription by the UK Government on November the 1st 2018. The Williams family thought when that law was passed Bailey would be able to get access to the drug. But they have been turned down by their neurologist and following a 2nd opinion too.
To date no new NHS prescriptions have been issued by any medical teams across the UK.