5 Reasons Why Waste Comes Back & How to Troubleshoot

When you flush the toilet, you expect that it will get rid of everything inside that needs to go down the drain, but sometimes waste comes back up, which can be gross and a sign that there’s something wrong with your pipes. There are many reasons why this happens, so let’s talk about what could be going on and how to fix it.

If your toilet has a flushing mechanism that works but the waste doesn’t seem to be coming back down, there could be a few reasons for that.

The main reasons that waste would come back up or won’t flush are stuck non-flushable items, grease clogs, old flushing systems, incorrectly adjusted water levels, or wrong-sized rings. Sometimes removing and replacing the bowl will do the trick; other times it’s best to call a plumber.

Let’s take a look at six common causes of toilet flushes but waste comes back as well as how to troubleshoot them. This may save you some headaches down the road.

1. Non-Flushable Items (May Include “Flushable” Wipes!)

Non-flushable items can clog your toilet and make it hard for the water in the tank to push them through. This can result in waste coming back up through your toilet, which is an unpleasant experience. To avoid this problem, never flush anything but human waste and toilet paper down the toilet.

How To Unstuck Non-Flushable Items

Using A Plunger

If you have a plunger available, use that first before any other steps to remove obstacles that aren’t too deep.  You will want to place the plunger upside down on top of the opening of the drain pipe where it meets with the toilet bowl. Make sure that you are creating a tight seal over the hole.

Use Sewer Snake

If the obstacle cannot be removed by using a plunger or if liquid continues to come out, then you may need to try using a sewer snake. A sewer snake is a long flexible tube with a hand crank on one end used for clearing blockages inside pipes.

The Old Wire hanger Trick

If you don’t have a plastic drainage stick, you can use a wire hanger instead. Simply straighten the wire hanger, so you can reach as far into the pipe as possible.

Twist the wire around to help break up whatever’s blocking the pipe. Push and pull slowly, so you can feel when something gives way. Remove what comes out until only clear water comes out.

Marketing departments like to advertise products as “flushable”, but any plumber will tell you they’re likely to create plumbing issues down the road. Make sure you only flush waste and toilet paper down your toilet so you’re less likely to have to pay for expensive repairs.

2. Broken or Damaged Sewer Pipes

Broken sewer pipes can be caused by tree roots, cast iron pipe corrosion, weak pipes, and shifting soil.

The best way to fix this problem is replacing the broken or damaged sewer pipes as soon as possible. Broken or damaged sewer pipes will require professional plumbing help.

What To Do About Broken or Damaged Sewer Pipe


Trenching involves digging a trench near the leaky pipe, attaching it to the sewer line with a connector that has an opening on both ends. A new pipe then runs from one end of the connector back up to where it needs to connect with your house’s main line.

Trenchless Sewer Repair

With this method, they create a small access point (a cleanout) at ground level and insert the machine into the pipeline under pressure. This is a less invasive method that allows you to replace a section of pipe without digging.

Image Credit: www.plumberoftucson.com

While we all want our pipes to never need replaced, sometimes too much damage occurs requiring them to be replaced. Make sure you hire a professional to handle any sort of pipe repairs or else you can end up with more problems than just a damaged pipe.

3. Grease Clog

A grease clog is a common plumbing problem that can be caused by cooking oils, animal fats and solidified cooking grease. This type of clog occurs when the grease hardens in the pipes and prevents water from flowing through.

When a grease clog is present, it’ll usually require professional help. A plumber will use a drain camera and other tools to locate the blockage and unblock your drains. Grease clogs are one of the most difficult types of clogs to remove because they’re so stubborn and often require extra steps such as applying heat or chemicals before removing them.

The only way to avoid this kind of clog is by preventing too much fat from getting into the pipes in the first place. If you do find yourself with a clog, reach out to a professional to get it resolved before it gets any worse.

4. Clogged S-trap or P-trap

An S-trap holds a small amount of water to prevent sewer gases from escaping through the sink or shower drain, and a P-trap is the industry standard. If either of these traps get clogged, it will cause waste to come back up into your toilet.

An S-trap without a vent can drain the water so quickly that it siphons the trap dry and exposes the room to sewer gases. In the world of kitchen and bathroom upgrades, P-traps are the standard, and when they are properly installed, they will maintain a water seal in the bottom.


Clogged traps should be addressed with a toilet auger which will unclog the pipe if you are able to reach them. Think of it as the next step after a plunger doesn’t work. Not many people have toilet augers at home.

They can be rented, but for those unfamiliar with toilet augers or too bad of a clog, a plumber should be called to assess the situation. There’s also a chance that there may be more than one type of blockage in the pipes, and you may need professional help if so.

If you’re searching online for what is an S-trap or P-trap, you’ll likely want to contact a professional to assess your situation. They’ll know exactly how to resolve your clogged S-trap or P-trap.

5. Toilet Flushing System is Old or Weak

If you are using an old toilet, it may not have the power to send all of the waste into the drain. The best solution for this problem is to replace your old toilet with a new one that has high-efficiency features and a powerful flushing system.

Sometimes there are some parts that could need replaced. A common issue is ghost flushing, also known as phantom flushing, occurs when the toilet tank flapper is no longer creating a watertight seal with the flush valve, causing water to unnecessarily leak into the toilet bowl.

Old Toilet

A toilet’s flushing power is affected by how well the water can be moved through its pipes. Old toilets tend to have narrower pipes which can lead to reduced water flow due to constriction or debris. Other factors can include how much of the water is used in each flush.

The best solution would be to replace the old toilet, but not all budgets may allow for a toilet to be replaced.

If you’re unable to replace the toilet, consider being more aware of your flushes. Consider things like using thinner ply toilet paper or only putting a small amount of tissue down at a time to help reduce strain on the plumbing.

Don’t flush anything other than human waste and toilet paper down the toilet as this could lead to clogs as well. Over time toilets will need to be replaced. Fortunately, many home owners can enjoy improved efficiency as well as a strong flush after replacing their toilets.

Using Drain Cleaner with Sulfuric Acid

Drain cleaner is not the best tool to use to clear a clogged toilet. Drain cleaners, like acid, can damage pipes, especially older cast iron pipes. When sulfuric acid comes in contact with metal, it can cause etching or corrosion which will often lead to leaks and other problems.

On top of damaging pipes, sulfuric acid is extremely corrosive. If it touches your skin, eyes or lungs it can cause burns or irritation.

Even if you’re wearing gloves and protective gear, you still need to avoid coming into direct contact with drain cleaner as it may still be able to penetrate through the protective layer.

It’s best to use alternative drain cleaners or other natural remedies that are safer for both your pipes and you. Let’s take a look at some at-home remedies that can be used to help unclog a toilet.

At-Home Remedies to Unclog a Toilet

If your toilet is clogged with waste, there are some tried-and-true ways to unclog it. Here are the most common methods and what you’ll need to get started.

Dishwashing liquid and hot water – Place half a cup of dishwashing liquid in the bowl of your toilet and add three to four cups of boiling water. Let sit for about 15 minutes before flushing the toilet.

Vinegar, salt, and borax – Pour a quarter cup each of borax and salt. Add half a cup of vinegar. Let it sit for 15 min before rinsing down boiling water.

Salt and baking soda – Mix half a cup of table salt with half a cup of baking soda. Let it sit for 30 minutes before following it with a pot of boiling water.

These are a few common home remedies that can help unclog a toilet that’s backed up, but sometimes it may require a professional. At-home remedies are great ways to help maintain your bathroom without having to call someone every time something gets blocked; however, if the problem persists or if you notice sewage coming out of your drains, it’s best to call a plumber.

When to Call the Plumber

If your toilet doesn’t flush, the first step is to see if you can clear it. If the water level in the bowl decreases but waste remains, try using a plunger or pouring liquid dish soap down into the toilet’s trap and letting it sit for a few minutes before flushing. If this doesn’t work, don’t hesitate to call a plumber!

Professional plumbers are able to properly assess what needs to be done, which might involve replacing pipes, valves, toilets and tanks.

It’s best to resolve the problem for when a toilet flushes but waste comes back. Some plumbing problems will require an expert to come out and take care of the problem on-site because the issues could be more serious such as leaky pipes from a broken main underground.

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