I was sitting on the toilet this morning, and all of a sudden It goes glump glump glump, and I look down to my dismay, and their was no water, it gurgled it up, but than it released it, and i flushed, and it worked. But than, standing near the sink, glump glump glump again, it sucked some more water up and released. Any thoughts what that is, is that a sump pump? Or just bad plumbing ?

WP Robot