שולחן ערוך אורח חיים · סימן פ״א

English

Laws of the Excrement of a Child, containing 2 s'ifim A child who has arrived at [an age that] generally other [children] similar to him can eat an olive-size amount of grain in [span of time] that an adult could eat a half-loaf, we distance ourselves from his excrement or urine.

English

If one was reciting [the Sh'ma], and saw excrement in front of them, they should go such that they put it behind them by 4 amot. And if that is not possible, for example, there is a river or another thing that prevents [going], they should go such that they place it 4 amot to the side. And one does not have to go back [and recite from the beginning] rather to the place they stopped. And according to Rabbeinu Yonah, if one was in a place where they should have given attention to [the fact] that there is excrement there, they need to go back to the beginning (And see above Siman 76, se'if 8)