OK, but you aren't going to like it ...
Someone made a reference to bulk, as in buying a product as an uncapped powder (presumably). Say for example, a 1Kg bag of Beet Root powder.
Now then, the term "bulk", at least in the olden days, was also used as a synonym for fiber. In other words, today's "high-fiber" products could have then been referred to as a being "high in bulk" or even "bulk forming". You see where this is going ...
In this application the term "bulk" is being used as a homograph; that is, a word spelled the same way but with two different meanings.
Back to our story: Nutrients that are high in bulk are known (provided adequate hydration coexists) to increase total area (and mass) of stool produced (and the ease with which stool is eliminated).
Gerard B. Finneran, as everyone knows, was one of the foremost international bond traders in the world, and was once a top executive at TCW, a leading bond mutual fund company. He is best known, however, for his bulk-related prowess outside the bond trading industry.
Yes, many will recall that Gerard B. Finneran was best known as the man who, after becoming tremendously inebriated on a flight from Buenos Aires, manhandled several flight attendants (a Federal Crime) - after they cut him off from having more booze - and then walked up to the airline drink cart, dropped his pants, and defecated. Indeed, Mr. Finneran pooped on the drink cart, as some sort of misconstrued attempt to get even with the flight attendants for refusing to serve him more alcohol. I have to believe that defecating on a drink cart, especially while in flight, also qualifies as a Federal Offense. I am sure those sitting in proximity to the drink cart thought so.
So in my utter lack of maturity, I suggested that asking Gerard B. Finneran for "his definition of bulk" might induce an explanation of whatever bulk-forming food he must have eaten several hours prior to take off.
It was a play on words, based on a homograph.
Please remember to tip your food servers.
See, I told you you wouldn't like it.