Our house is 3 years old and we have our own septic system. We have had problems flushing all 3 toilets in the house since we moved in. Our plumbing contractor send a guy over after we were there a couple of months to check it out and he couldn't find anything wrong. I spoke to them again lately and they tried replacing one of toilets. This new toilet is having as much trouble flushing as the other ones. We have never heard any gurgling noises from our sinks or tubs.
Answer:
It is time to have another plumber take a look at the system because this one either doesn't know how to fix it or knows and doesn't want to go to the trouble.