www.paediatriccontinenceforum.org/wp-content/uploads/2018/01/Paediatric-Continence-Commissioning-Guide-2014-PCF-2018-version.pdf
If you look at section 1.8 on page 15.
Section 1.5 on page 11 describes the population to whom it applies - There are approximately 900,000 children with a continence problem (See 1.2). This includes children with toilet training difficulties relating to a learning difficulty or a physical disability.
From tips on caring for a child with a disability = www.nhs.uk/conditions/social-care-and-support/caring-for-a-disabled-child-tips/
If your child's health condition affects their ability to control their bladder or bowel, their doctor may be able to refer you to a continence specialist.
An occupational therapist can advise you about special potties or toilet seats if your child needs help with sitting, or about any bathroom adaptations that might be useful.
A physiotherapist can advise about issues such as moving and handling your child or finding the best position for your child to be able to use the toilet.
Your local health authority's incontinence service may be able to supply items such as larger nappies, pads and bedding protection once your child is over a certain age (this may vary from area to area).
If they're unable to do this, they can tell you where you can buy them privately but push for an NHS service first, I have heard of some places like in your pp saying we can't help and so you spend £100s a month (and I'm guessing you are like the rest of us and don't have it to spare but that's an assumption hugs)
If you have a water meter and your child's health condition means that you have to do a lot of laundry, you can apply to your water supply company to cap the cost of your water under the WaterSure scheme. Ofwat has contact details for water companies.
The Family Fund can also give grants to low-income families for a washing machine or tumble drier. (this may help someone else if it doesn't help you)
For the bed, I have a hospital bed as it rises up to the level the carers need to handle me and the middle of it is always covered with inconti sheets (not the ones like puppy pads that hospitals have) but comfy ones,
The brand name is Kylies but these are far too dear. I use an unbranded one and it works as well. It was a one-off purchase and then I replaced some of them 3 years later. They work out about £6 each and absorb up to 3 litres at a time
They absorb any urine and while faecal matter can get on them it pulls any liquid into the bed pad and then the actual matter can be wiped off with a couple of baby wipes and put into a nappy bag and into the bin.
I have bought a supply of "red bags",(50 for about £8 in postage) they are popped into one along with any clothes/nightwear that got it and the red bag goes straight into the washing machine still tied. The most of the bag dissolves in the machine and take out just the remains of it and bin,
Tena lotion is good for keeping skin right with all this going on but while I know some Drs won't prescribe it (my district nurse asked me how I managed to keep skin intact),
I am prescribed dermol lotion by the DN team but the script is done by GP so I advised the nurse that it does exactly the same as Tena and can be used in the shower as well. So prescription requests for it have gone up around this area as they are prescribing it for all who need it as didn't know it worked the same if not better
This is some ramblings which may or may not help but hope it does.
It's like everything else but to get services which he might need long-term (but I hope not), you are his best advocate.
Best wishes to you and your son. (((hugs)))