I am going to start getting checked for this but was curious to know if Mast Cell can be limited to only the GI tract? I guess the only other thing weird that could 'maybe' be related is my ears will turn red hot at times, usually around times when I feel really bad.
Anything involving GI dysmotility or inflammation will ramp up GI mast cell activity so it's not necessarily a "mast cell" problem, just a reaction.
That said, there are a couple of specific GI mast cell conditions, Mastocytic Enterocolitis and Allergic Mastocytic Gastroenteritis and Colitis.
Treatment is the same as for MCAS, MCAD though - H1, H2 blockers, mast cell stabilisers of cromolyn sodium or ketotifen, maybe a DAO supplement to dampen reaction to food histamines.