Well, do you or any one you wash dishes for have bowel problems? Dish washer detergents often leave a saponin residue or glaze on them, stuff to leave them sparkly shiny or crystal clear or whatever. Saponins cut fat and break surface tension of fluids, so they can damage the mucous membrane in your gut. This can cause all sorts of bowel problems like IBS. If anyone in your household deals with anything like that, try cutting out the dishwasher, or rinsing the dishes really good after they come out and see if the problems alleviate.