Toddler refusing a bath

[24HoursFromTulseHill]

DS is 2.3 years old and has been having nightly baths since he was a baby.
Last week he had a couple of upsetting experiences in the bath and now refuses to go in it (he did a poo in the bath one night and the following night I needed to wash his hair when he was too tired and he got upset).
I don't think it's a sensory thing, because he still enjoys washing his hands at the sink and playing with water in the garden.
He now refuses to go in the bath, regardless of whether it's empty or has some water in, so we've been doing flannel washes next to the bath instead but it's been 10 days now and his hair needs another wash.
I've tried coaxing him into the shower with little success.
His nursery workers say to keep on exposing him to the bath every night but not forcing him in it, to keep the familiarity and build up his confidence.
I've tried going in with him or dangling my feet in the water with no success. New bath toys haven't worked either. Our bath is a deep roll top bath that he needs to be lifted in and out of and he's an absolute control freak so I think that's part of the issue.

What else can I try or how long might this go on for?

Lift him in, he's small and be there ready so nothing happens that is unexpected for a few baths.

Not RTFT so don't know if it's already been suggested but what about getting in with him and filling it when you're already both sitting in it? My autistic 3yo screams and thrashes in the bath unless we do it like that. We use the bath as a place to sit and play with bath toys and then slowly add the water and then she finds it easier to be washed when I'm not looming over her.

@24HoursFromTulseHill What happened with this in the end? We are going through the exact same thing with our 2 year old at the moment 😫

@itsawildride I can't remember the full details but he did eventually get over it.

I think we started to "bounce" him, with my husband lifting him up and down going "boing" and then doing a bounce over the bath so his feet got wet, another one on the floor then back over the bath again, getting him a.little bit wetter each time.

We definitely didn't just chuck him in, as was suggested by some people at the time, which would have terrified him even further. Gently keeping him exposed to it and trying different fun ways to get the water on his skin worked best.
The whole period was about 4 weeks of bath refusal, with strip washes with a flannel every night to keep him clean.

He's now 3 and a half and loves his nightly bath - still not a fan of hair washing so we stick to weekly for that.