Do you weigh more or less after you fart?

Dear Cecil:

You haven't had an intestinal gas question for months now, so … how does gas affect one's weight? After a prolonged episode of expulsion, will one weigh less?

Cecil replies:

Younr question undoubtedly arises from a deep-seated spiritual sickness, Annie. However, you have opened up an interesting line of inquiry, inasmuch as there is some reason to believe that after a good toot you weigh more — slightly. Two of the principal components of flatus are hydrogen and methane, which are both lighter than air. Thus it is conceivable that when you deflate, as it were, you lose buoyancy and add poundage. On the other hand, it is not clear what the ambient pressure of gas in the intestines is — a critical factor, since even a light gas under sufficient compression weighs the same as or more than air. In hopes of expanding the pitiful reaches of human understanding, therefore, Cecil offers the following proposition to the research community: You provide a practical experimental design and willing vict—er, subject; I’ll supply the beans.

Send questions to Cecil via cecil@straightdope.com.

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