Occasional blockages in the sink, tub, or shower drains pipes are a truth of life. They are normally brought on by localized obstructions in the drain trap or branch drain for a single component. However, if you have numerous fixtures that are draining pipes slowly or not draining at all, the problem might be in the primary drain or sewer line in your home.
http://rowanwjyf395.aircus.com/-a-simple-definition