@Jenny_M
I don't want to intrude upon your medical issues, but you might find the Attain device helpful to strengthen muscles and improve control. It is fairly new to the market.
https://www.incontrolmedical.com/attain-device/?
While it is promoted for female bladder control, it is also approved to strengthen anal muscles in both women and men.
And it works. It's just not 'nice' to advertise that function.
In use, the probe is lubed with a special conductive jel and inserted rectally. After insertion, the probe is inflated for a good fit and the e-stim session started.
Each stim pulse train caused your anal muscles to contract and squeeze the probe for a few seconds, then relax. The stim intensity is adjustable from mild to very intense The device essentially takes control of your anus gives your anal muscles a workout by making them repeatedly clench and release.
It is suggested that you pee and poo before a session, but the device does not have a laxative effect. Sessions take about 10 minutes and are not messy, except for some lube. The device works on AA batteries and is easy to clean.
Also, there are meds to firm up poo and reduce urges, but I presume you know about those.