try to take a bath of a hot water.. but a hot water that not will burn your skin..
then wait if a small air bubble will come out in you neck, back, chest, arms..
OR
in the hot tub.. just lay in there with a hot water and wait if bubbles will come out.. like your being boiled..
the small air bubble look like a round red dot if you look in the mirror..
when you have it, means you have this "leaky gut syndrome"