Customer got main sewer line backed up for both restrooms same as happened last November, we removed one of toilet , cleared line with camera , we also did camera inspection. We found clog was at tie in point next to three compartment sink before exit the building, because of this repeat problem within three month or so , we have determined this back up is related to the pipe installation at tie in point based on where we cleared line and camera inspection. To fix this problem permanently we will need cut floor in the kitchen and redo section of line with new pipe and fitting . Call chen plumbing 6786216363 ask Tim chen for questions