Toilet training/bms

[Busy ECE mommy]

I posted a while ago about a 3 yr old boy who is trained as far as pee goes, but bms are a nightmare. Spends about 15mins in bathroom, and generally still has 1-2 bm accidents a day(after 6 weeks of training) BMs are very loose and messy and often leak out of pullup. On the rare occasion that it actually ends up in the bathroom, it is everywhere(down legs/on walls/floor etc) I have encouraged self wiping when it happens in bathroom, and assist him as needed, but now it's usually leaking onto clothes out of pullup while in the playroom. When he has frequent bm accidents, he will tantrum for 10-15 mins if I try to wipe him, and will upset himself to the point of vomitting. Of course parents say accidents NEVER happen at home LOL, and no tantrums either at home. He can hold his pee, but cannot tell me he is about to poo, or cannot tell me he has gone. The same goes at home-cannot verbalize has gone/about to go. Usually I detect it by smell, or by a huge tantrum. If you had a child who was pee trained, but not poo trained with numerous accidents, would you ask parents to go back into diapers, or put the hold on training for now? Help!!