One is forbidden to recite the Shema, or any other words of Torah, in the same room as excrement.
One sage, Rav Yosef, asked another, Rav Huna: Is one permitted to recite the Shema when there is excrement beneath a bed whose height is between 30 and 100 cm and the person is reclining upon the bed? The sage answered, “I do not know.” Why did he specifically ask about a bed in that height range? It was clear to the sage who asked the question that on a bed lower than 30 cm one may recite the Shema, for up to that height the bed forms a closed container above the excrement. Upon a bed higher than a meter, it was clear to the sage who asked the question that one may recite the Shema though there is excrement below, for the bed is considered a separate domain, and it is considered as though the recitation is occurring in a location different from that of the excrement.
(Babylonian Talmud, Tractate Berachot 25b)