We have two pressure assisted toilets in a house that is around 5 years old. This morning I was in the next room to one of our bathrooms and a hear a gurgling noise. I go in and check the toilet and the water level is down. I try to flush it and the it doesn't flush quite right. It takes about two flushes to get a couple of pieces of toilet paper down. It fills up then bubbles or gurgles (I can really tell which it is) at the very end of the flush cycle and then the water level in the bowl drops again. I went to check our second toilet and it's bowl is not filling all the way and you have to flush twice to get the bowl completely empty. I never hear gurgling from the second toilet at the end of its flush cycle but it never even fills up all the way. The second toilet is in our master bath so you wouldn't be able to hear it gurgle unless you where in there with it at the time of gurgling. I went outside and looked from the street and it seems that we only have one outside air vent coming from our house. We are on city water and sewer. The toilets where fine this morning when I woke up. I started a load of laundry and a load in the dishwasher I noticed the toilets after I started those. However they ran through both of there cycles with out any noticeable problems. We went into our crawl space and didn't notice any water leaking from any place. Can you please help us? We are at a loss. We are a young couple who live away from their family and even after talking to parents on the phone parents are at a loss.

Any "gurgling" you hear from a fixture that has a trap tells you that something's attempting to vent through that fixtures trap seal. That means a clogged vent that has to be snaked and cleared.
I went outside and looked from the street and it seems that we only have one outside air vent coming from our house.
You have a problem. Unless you have plumbing skills you're going to hafta call in a plumber with a sewer machine. Sorry kids, but it's not a case of me "walking you through" renting a sewer machine and going up on the roof to snake vents.
Let me explain. Sometimes the builder doesn't want multiple vent stacks poping all over the roof so we're ordered to revent or tie back all the vents in the attic to one main vent exiting the roof. That's great for looks but bad if you ever have to snake them.
To clear vents that are revented back in the attic the plumber will have to take his machine up in the attic, locate the correct vent and cut it loose. He will then snake the vent and come back down to check his work. If everything's OK then back up he goes to couple the vents back. Not a job for the average home owner. I don't know where you live but it gets blistering hot up in a attic in my area. I'm just glad I'm not going to be the plumber that you call. Good luck, Tom

The toilets are not draining at all know and all of the drains in the house are making noises. We went onto the roof and used the garden hose on it and it all went down fine and dandy. My husband went under the house and took off the drain clean out cap and a huge amount of raw sewage came FLYING out of the tube. Well over 600 gallons came out we are pretty sure of it. And it never showed signs of slowing down. From what we can tell the main line comes out of our house and makes a 90 degree turn towards the street where it meets up with the city sewer. A lot of family thinks there is a clog around the connection between our lines and the city or that there may be a huge clog in the city lines. What does it sound like to you guys?

If you really got 600 gallons you have a city main blockage. You also have a crawl space flooded with raw sewage, not just wet but flooded. Now if you really got 6 or 10 or if you have a big two story house maybe 20 gallons, you have a blockage between you and the city main. If the city main is blocked, the sewage will keep coming out the clean out as long as you have it uncapped.

WOW ! I would not want to be the guy removing the clean out plug under the house - and then crawl as fast as I could in 16" of vertical space so I don't drown in my own sewage !

Well, at least you know where the problem is: it is in your main sewer and it is most-likely blocked somewhere in front of your house or further towards the street... Do you have an exterior Clean Out?