Back in the 1950s +/- being very sure a sick person pood every day while sick was considered important. After all, for many illnesses there were no ‘cures’. Actually, even today, the same is true and the only treatment is symptom relief.
Anyway, this theory resulted in many moms, nurses, and doctors giving laxatives, suppositories, or enema to anyone who claimed to feel sick. After all, being made to poo is not really harmful if done occasionally. Also, knowing this was certain to happen, was a disincentive for those feigning illness to avoid a quiz or something similar.
It is interesting that some ‘cold meds’ of the day included a laxative:
In fact, this treatment does make some sense. In my persona experience, described elsewhere on this site, if you don't poo within the first day or so of becoming sick, the constipation can easily get worse and after several days to a week or more laxatives are useless and the only thing that does work is a bagfull of warm, soapy water.