I do not have difficulty passing stools after enema. Normal BM resumes in around 2 days after enema is done.
I do take acidophilus tablets before and after enemas, as well as natural kefir on regular basis.
I do enemas in the morning on empty stomach. I normally start eating shortly after enema. Kefir, fruits first. Full meal in 2-3 hours. The painful sensation starts several hours after the first food taken - maybe after 4 or 6. That's why I think it has to do something with food reaching the colon.