After having my septic system (tank) cleaned about a month ago, I've noticed a foul odor in the bathroom of the master bedroom. I've also noticed the smell outside near the master bedroom. It's not smelling in any other part of the house. A couple of weeks later I noticed that the kitchen sink is not draining properly, but only on the right side. The bathtub isn't draining properly nor are the toilets flushing properly. The toilets flush as if they're not getting enough pressure or water flow. After flushing the toilet twice and sometimes a third time then it will flush where you can hear the flushing sound that lets you know it has flushed.
What could possibly be wrong?