 According to two researchers, Nesse and Williams, diarrhea may function as an evolved expulsion defense mechanism.As a result, if it is stopped, there might be a delay in recovery.They cite in support of this argument research published in 1973 that found that treating "Shigella" with the anti-diarrhea drug (Co-phenotrope, Lomotil) caused people to stay feverish twice as long as those not so treated.