Monologue on the topic of seratonin and 'being full of **it.'
As can be seen in the above excerpted dissertation on the 'second brain', the mythical 'gut', the health of mind is closely intertwined with that of the bowels.
Does this mean that if one is constipated one is 'full of ....'? Or conversely if one is 'full of ...' is one constipated?
There are a number of ways to find out.
I suggest research as being efficacious.
Make a note if someone says 'you're full of ....'. Check the state of the bowel movements. After about three events, or non-events as the case may be, it may be safe to come to a tentative conclusion.
Perhaps you are sufficiently perspicacious to be able to divine the above for your self.
Further : Because it's possible to not be aware of pain in the gut on a conscious level while the sub conscious is very well aware of it, the sub conscious can excert pressure on the conscious and make one act out, for example, aggressively (perhaps determined by the degree of negative or otherwise, potty training one had to endure) in response to outside stimuli.
One may feel an overweening need to repair cellars, clean gutters, solve crimes, put things right or otherwise act out the state of ones bowels. The situation may present itself in many odd ways, or not.
Whatever, as has been said, fibre is your friend. It helps to lose weight and to exercise.
To feel ok about however you may be : meditate.
Cheers.