Now there can be a couple things going on.
If there is a degradation of the pipes it will need to be dug and repaired. I had a home owner we used to power rod their sewer once every two years. Then out of the blue it started to clog every month. This was before they had cameras for sewers. We located the trouble spot dug down, turned out the cast iron line that was outside the house had corroded and clay was washing into the ling causing the stoppages.
Now another instance I had a home owner that we rodded the sewer every two years to remove tree roots. It too started to clog more often in this case almost weekly. But this time the blockage was not outside like it used to be, and there where no tree roots. I asked her if she recently changed toilet papers. She did she bought a huge bag of the extra soft paper, she used to use Scotts. Told her any toilet paper that says new and improved is evil. She switched back to a normal paper, and things are back on schedule.
So if your sewer is backing up chronically,(more than once a year) it just means the problem has gotten worse or its the paper. You will need to get the line televised after the next rodding, to inspect the pipe and locate the problem spot.
