Yes it is your reaction to food, large food molecules, incompletely digested which your immune system reacts to.
Quercetin has some antihistamine effects so it might be worth looking at that for the time being. Be aware that very large doses can cause damage so do not go overboard on it popping capsules every hour. Some foods are high in quercetin BTW. Onions in particular Red Onions are high in Quercetin and so are some Apples such as Granny Smith apples. See the link below for some details. If you search for quercetin and kidney it should show details about using too much. Food is safe but supplements are less so if taken in large doses. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6273625/
Some other things worth researching are Quorum Sensing Inhibitors which stop micro-organisms inside biofilms from communicating between themselves and assists biofilm removal. Then there are Efflux Pump Inhibitors which also have a relationship with QSI's and they help prevent micro-organisms from eliminating antimicrobials making the antimicrobial more effective.
BFB 1 & BFB 2 which consist of essential oils, these also have somewhat limited EPI effects.