I assume that the 11 burst pipes were water supply lines, and that these were repaired and that your plumber did not change the DWV system or replace the toilet (i.e. with a “water saver” model). If so, and if your toilet flushed OK before, I can’t imagine why it doesn’t flush properly now, unless somethings wrong with your toilet (RP mentions what those problems could be). Another possibility is that whatever screwed up your supply lines (an earthquake??) screwed up your DWV lines as well.