Toilet Flushes But Waste Comes Back | Troubleshoot

Does your toilet come with waste items and water after the flush? Toilet blocking, overflowing is so unwanted yet, common problems nowadays. 

This is something to concern about if your toilet brings back dirty items even after flushing. 

Not only can it generate massive disturbance, but wastewater may also produce your entire housing infections. It is toxic for everyone. 

Today’s focus is on why the toilet flushes but waste comes back and how to fix this mess.

Why Toilet Flushes But Waste Comes Back?

Waste like water, poop, toilet paper, soil water, etc comes back sometimes while flushing- This happens due to the toilet clog. 

But what if there is no clog present, still waste products return?

Several reasons hiding behind the toilet flushes, but waste comes back. 

Reason1- Why does my toilet back up sometimes due to CLOG

Clogging is the main reason for the toilet’s waste product backup. Blockages can occur in various parts of a toilet- such as a bowl clog or something becoming stuck in the trapway and causing a clog.

Check if there is any blockage present or not. If, yes then remove the objects by using of toilet snake or plunger.

Read more- Simple way to remove the clog with or without a plunger.

Sewer Line Clog 

Many times main sewer line may be clogged for any reason. Due to unclear duct, whenever you use the toilet, all waste materials return to the bowl.

However, the main sewage line may be affected if the sewage is back up for your entire home.

The construction of the drainage system is occasionally compromised, and the sewage line is ruptured- This stops the flux of water and wastewater and so returns.

The water contains a stinking odor( sometimes even poop). 

The blocking items are waste food products, plastic toys, hair, hygiene products for females, Q-tips, paper, or even non-soluble items.

Whereas, if congestion impacts just one substantial part of your household outlets, it must be in the backup routes.

What To Do If Your Sewer Line is Blocked?

Check twice and confirm the sewer line is the actual problem. After confirming, contact an expert. When it’s about the sewer line, without an expert, you can’t do anything.

Otherwise, excessive blockage not only gets the waste back also can cause overflowing a toilet.

Clog in the Trapway

Trapway clog is the most common issue. Trapway is generally “S,” “P,” “U,” shaped a bent shape pipe. 

Toilet Trapway is joint to the sewer line. If any item stuck there or mineral deposit may block and narrow the canal, waste materials come back often.

What to do if Trapway gets blocked?

To unclog a trapway use, a plunger or snake it up. 


  1. Take a flange Plunger, wear protective gloves.
  2. Place the Flange Plunger on the opening of the bowl.
  3. Push once to create the seal and start the suction.
  4. Now, Push and pull the Flange. So it maintains the rhythm.
  5. Do the job for about 15 minutes and see if the water level decrease or not.
  6. If so, Plunge again for few minutes and again flush the toilet to see what happened?
  7. Note that– if the water level increase instead of reduction, stop plunging and call an expert.

In this case, you see the toilet flushes, and waste doesn’t come back this time- which means you have a clogged toilet trapway. 

Toilet snake

The toilet snake is an extremely useful tool for unclogging any object in the toilet trapway, and it can even go deep down.

The toilet snake goes through the trapway line, where the wax ring connects to the drain on the floor.

The Toilet snake can make a bunch of metal scratch marks, so make sure you properly do the job and get a plastic protective sleeve of a toilet snake.

  1. Push the sleeve all the way down to the bottom, where the twisty hook is present.
  2. Now insert in the toilet that way so the bend angle it can go properly.
  3.  The scratches are not formed. Now hold the protective plastic sleeve firm and start pushing.
  4. Using the handle and pushing the snake up and down, or you can twist.
  5. For better clearance pushing up and down at the same time twisting as well simultaneously.
  6. You might have to do this for 10 or 15 minutes.
  7. Now flush the toilet and watch out for any improvement.
  8. Now remove the snake pull all the way up, twisting and loosening it. 

If you don’t like to use Plunger, Toilet Snake is the best alternative tool. You can use it whenever you want or add it to your daily toilet cleaning routine.

Flush the toilet once and see if the waste has come back? If so, then clogging is not the reason.

The main reason is something else.

Waste Water Coming Back into Toilet Because of the Air Admittance Valve (AAV) Issue

The Air Admittance Valve (AAV) permits airflow in the drainage system while preventing unwanted odors from exiting at almost the related moment.

The majority of residential house drainage facilities are ventilated straight via the roof. 

Air Admittance Valve is a vital aspect of plumbing. Because it not only discharges nasty and toxic gases from the house, can also maintain air pressure inside the sewer network.

AAV also prevents the formation of the vacuum of the water that blocks the waste from coming back. AAV generally works in one way. The air goes outside and maintains the same air pressure.

While you ask yourself, ‘why does my toilet backup sometings or human waste’ the problem is your house Air Admittance Valve. Somehow it is broken or blocked.

What to do If AAV is failed to doing its job?

  1. Verify other faucets of your house and check if the same problems show! Climbing the rooftop, where your vent pipe is located, and clean with a hose.
  2. Replace the AAV if it doesn’t manage.

To prevent further blockage, use these tricks

  1. Always be careful about what you have flush down.
  2. Instead of any object flush down, use a bin and throw all items there. Sometimes your throwing object stuck the sewage tunnel and heads to a disaster.
  3. If you have faced the same problem often, you need an annual plumbing inspection.
  4. Or, to avoid spending money- clean all faucets and drainage systems with good harmless cleaners.

When Do You Need A Plumber?

Toilet clogs effortlessly can be clear, unfortunately not every time. The unclogging process can make anything bigger if your luck is lousy that day.

Always work on tiny blocking. However, for this type of inner blockage, it’s very vital to consult a plumber.

Final Words For Toilet Flushes But Waste Comes Back

If, you keep your plumbing system well. Know how to manage it in an urgent situation. You can minimize the wastewater reserve damage. 

Perhaps are many items that are more unpleasant and challenging for homeowners than a wastewater reserve.

Not just produce an enormous mess, but sewage may also cause infections throughout your property. It’s harmful. You must call the specialists when nothing of such DIY alternatives works.

FAQs1- Can Stuff Come Back-Up The Toilet?

Yes. Anything can return to the toilet bowl after flushing if the central sewage system is broken. A toilet never depends on just a flush and the handle. The whole process goes through different matters like air pressure, vent pipe, the toilet itself.

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