Choked-up pipes can act just like clogged pipes, but they are actually two different plumbing issues. A clogged pipe can easily be cleared. A choked-up pipe has years and years of residue, rotting materials, and metal flakes caked together and stuck to the walls of the pipe. It is nearly impossible to clear a choked-up pipe. Here is more about what causes this plumbing oddity and some plumbing services and solutions that your plumber will apply if it is discovered that you have a choked-up pipe.
Think Arterial Plaque and Artery Walls
A choked-up pipe is like a human artery with really bad arteriosclerosis. There is this massive buildup on the walls of the artery, and it just gradually accumulates over time until the whole thing is choked off and nothing can get through. The same holds true for pipes.
Organic material, soaps, minerals, hard water, and flaking metal from inside the pipe accumulates until the walls of the pipe are choked off by this super-hard mass of stuff that refuses to budge even when your plumber attempts to jet-flush the pipe. Eventually, the pipe refuses to allow even water to go through, and then you end up with a backed-up sink, tub/shower drain, or toilet, and the backed-up wastewater refuses to move and you end up bailing or avoiding using the plumbing fixture because of this problem.
Your plumber, upon assessing the choked-up pipe situation, may want to investigate with a sewer camera. The camera will show him/her just how bad the situation is and whether or not the pipe can be cleared. If water can still get through, it may be possible to use a chemical solvent to dissolve the mess that is in the pipe and/or use a power auger to grind away and the hard buildup that is stuck to the walls of the pipe and choking it off.
Your plumber is likely to try the latter first, since it is less damaging to your pipes and safer for the plumber to use. If that does not seem to work, the plumber may resort to chemical solvents that will eat away at any decayed material and/or calcium, lime, and rust deposits. The hope is to dissolve the organic stuff that is rotting and sticking everything else together, and dissolve the calcium, lime, and rust deposits that harden into rock-like substances. If none of the above work, the plumber will remove and replace that pipe entirely.