Hi OP. I have a 6 year old who we have had no end of toileting problems and we have inconsistent bed wetting too.
It tends to come in waves of several nights wetting, then it will be ok for a while. Then she might have the odd night wet. Then she might be dry for weeks before wetting again. So I am here for this!
A few questions first.
What are their toiletting habits like generally? Do they always realise they need to go?
Do they have any accidents or wetting (even little bits) in the daytime?
Do they avoid going to the toilet / deny they need it when they clearly do?
Do they ever get poo smears as well as any wetting?
My daughter is almost certainly ND. She hates missing out on things and will avoid going to the toilet at all costs to avoid missing out on absolutely anything.
I also think her interoception (feeling of needing to go) might be less than that of a normal child - she will often only realise or admit she needs to go once she's desperate.
She also has PDA tendencies and will avoid going if we tell her to go.
I believe the main cause of wetting (for us) is trying to hold poo. She doesn't like pooing, so even if she's needing a wee, trying to hold the poo makes her also hold the wee and she then ends up wetting herself.
As she holds poo, it puts pressure on the bladder at night and she wets the bed more often.
Things that help:
Laxido - one or half a sachet a day (prescribed by GP.) Softens poo so she can't hold it. She poos more regularly/ closer to when she needs to go, and it tends to stop the bed wetting. We used to give it regularly, now we give as and when she needs it or we'll do a stint of a week or two.
Encouraging her to poo before bed EVERY DAY - we have a routine where she has to try a poo each night. If she can't do one, we make her laugh by doing silly things and 9/10 one comes out. She ALWAYS tells us she doesn't need one - so we don't allow her to not try. If nothing happens after making her laugh, we say ok she has tried so she gets off and goes to bed.
Trying to get her to drink more/ eat more fruit!
Not allowing highly engaging activities without a toilet stop first. So eg. if they want to watch telly - I know for a fact they won't break off for the toilet, so they have to try the toilet before it gets switched on.
I realise most of these are around getting them to go to the toilet when they need it, and to avoid holding. But this has absolutely worked for us.
And re the laxido - our daughter isn't constipated and poos regularly. So you may think why would this help. But it reduces the holding, which in our experience helps with bedwetting!
Also - When it got overwhelming for me with washing, I put her into night time pull ups. She's old enough to understand it's not for weeing in, it's just in case of accidents. Helped MASSIVELY while we got to the root of the problem and saved my sanity. It's not a step backwards - so don't feel like you can't do this. Make life a little easier for yourself. I used them on holiday for peace of mind too.