Matzah constipated Chazal

Lest one think that matzah causing constipation is a modern phenomenon, consider this gemara in Shabbat 110a:

R. Joseph said: Egyptian beer consists of one part barley, one part safflower, and one part salt. R. Papa said: One part wheat, one part safflower, and one part salt. And the token is sisane.¹⁷  And it is drunk between Passover¹⁸  and Pentecost; upon him who is constipated it acts as a laxative, while him who suffers with diarrhoea it binds.

Rather than saying that it is only efficacious during this time, between Pesach and Shavuot, say that this is when they required its use.

:)

Rav Pappa was a beer salesman. Does he have greater knowledge into the identity of Egyptian beer than Rav Yosef? After all, it is more common to make beer from barley than from wheat. And so, given that the recipe is otherwise identical, Rav Pappa the beer expert could be correcting this statement of the earlier Rav Yosef.

And it appears, based on very cursory Googling, that Rav Pappa is correct in his recipe for Egyptian beer:

All the former research showed barley and emmer wheat were grown in ancient Egypt. It was emmer wheat that the ancient Egyptians used to make beer at Tell el Amarna. Archaeologists saved the preserved emmer wheat on the temple kitchen floors. 

The alternative is that each heard competing traditions, and so both are recorded.

As you might guess, I am a bit behind in daf Yomi.