Over saturdayhouse lunch, the discussion turned from dating bulemics to the problems experienced. Because we like problem-solving (in all its socially dubious forms), we noted that bulemics would probably prefer to have food taste roughly as good coming back up as it did going down.
The reduction in taste probably comes from the strong acid of bile, followed by the mixing together of foods. Simply quaffing a strong base prior would work, however the body would compensate by increasing bile production over time (not to mention that strong bases pose similar problems as strong acids).
A possible win-win (start cringeing) lies in using a prostaglandin like dinoprostone (commercial Cervidil) which reduces bile production in mammals. Some testing required, however reducing food intake to one or two food types over a meal might make for a more pleasant purge. Also, as an abortifacient, females dosing this would also not need to shell out additional money for the pill.