Toilet Smells Like Sewage When Flushed – 5 Causes & Solutions

Written by

Paulk Webb


Freddie J. Hagopian

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toilet smells like sewage when flushed

If your toilet smells like sewage when flushed, it indicates possible problems with your toilet plumbing and sewer systems.

If addressed early on, this could improve and make your toilet a good place to be in. The experience can make you feel anxious and irritated. The stench not only enters your nose but also gets into your head.

By knowing what its causes are, a stinking toilet could be resolved without hassles. Here are the explanations and solutions.

Causes of Sewage Smell and Solutions

1. Busted or Loose Toilet Wax Ring Seal


A busted or loose toilet wax ring may be one culprit when your bathroom smells like sewage. The wax ring is crucial to your toilet’s integrity as it seals the bowl to the floor and drain pipe.

Therefore, if you notice water pooling around the toilet, check the wax ring. You can also identify this issue if your toilet bowl fills unevenly or wobbles when you sit on it.

What to do?

To get rid of sewer smell from toilet, try applying caulk to the seal and base bolt holes. If this doesn’t work, you already need to replace the wax ring. For best results, call a plumber to get it fixed properly.

2. Damaged Toilet Bowl


Cracks often happen due to the wear and tear of your toilet bowl. Unfortunately, this occurs beneath the bowl and is usually not very visible, so we can notice it right away.

When this happens, water leaks out, letting sewer gas escape as well every time we flush the toilet. It’s one common reason why your toilet tank smells like sewage.

What to do?

It’s a serious issue if your toilet bowl is cracked since it can lead to flooding the bathroom. If this happens, contact a licensed plumber to replace it for you. Better be safe and secure than sorry.

3. Blocked Toilet P-Trap or Drain Pipe


Obstruction of the P-trap or drain pipe happens when objects get clogged in the pipeway. This blockage unnecessarily creates build-up, which in the long run causes the smell when you flush.

What to do?

To get this problem correctly assessed and resolved, it’s always best to call a professional plumber to check and repair the pipe and trap.

4. Obstructed Toilet Vent


A sewer vent is an important part of your toilet system as it allows sewer gas to escape, dissipate outside, and regulate air pressure.

If your toilet smells after flush persists, vent blockage is possible. Blockage could be due to birds building their nest or trapped rodents or birds.

If blocked, gas could find its way to your bathroom and make it stink whenever you flush. Even a new toilet smells like sewage if this happens.

What to do?

You should identify the specific area where the obstruction is and remove the blockage. Frost forming on your vent during winter also needs to be regularly checked and removed if required.

5. Dry or leaky P-Trap


There are two instances when a sewer pipe trap becomes an issue – it has dried up, or there’s a leak.

Used to trap and hold water, the P-trap is a U-shaped pipe connection that seals the sewer line. When a toilet is not used for a long time, the water in the P-trap evaporates, allowing sewer gas to leak out to the toilet.

When there’s a leak in the P-trap, the water sealing it empties, allowing sewer gas to escape through the toilet.

Read more: P-trap vs S-trap toilet: what is the difference?

What to do?

To get rid of toilet odor in case the P-trap dries up, just open your faucet and get the P-trap filled. If the smell remains, then there’s a leak.

A leakage already needs professional assistance; thus you need to call your plumber. Doing it yourself may result in improper repair or installation.

Frequently Asked Questions


Is the toilet smell bad for your health?

Yes. Smelling sewer gas when flushing toilet always creates an uncomfortable or uneasy feeling. This toilet stench mostly forms methane, a dangerous, colorless, and odorless gas.

Methane poisoning could even be deadly if formed in large amounts over a small area like your toilet. It is highly flammable and causes dizziness, nausea, vomiting, suffocation, and, worst, loss of consciousness.

A stinky rotten egg smell after flushing the toilet, on the other hand, usually originates from the formation of hydrogen sulfide gas produced by sewer bacteria. Just like methane, it poses a health hazard.

Can sewer gas go through the toilet?

Yes, unfortunately. If you have your toilet smell like poop after flushing, you have sewer gases coming out through the toilet. Or, if your toilet smells gross after flush at night, a gas leak is to blame.

This happens when sewage gas comes back, which takes place when you hear that gurgling sound after flushing.

What other causes make a toilet stink like sewage?

Though not surprising, the presence of microorganisms in the drain pipe also causes that obnoxious sewage stench.

Microorganisms like bacteria also remain in your toilet bowl, making the smell every time you flush. This occurs fairly often in hot and humid areas.

Is using chemicals always needed to remove sewage smell in toilets?

Not necessarily. As an initial step, you can use vinegar and baking soda to neutralize bacteria during flushing.

But if your toilet water smells bad or your toilet smells like urine after flushing already a few times, applying commercial disinfectants and deodorizers is the way to go.

In case when your toilet smells like rotten eggs after treatment, you need to get professional help ASAP.


Toilet problems like smell from toilet after flushing or your toilet smelling even after cleaning can come from issues with the wax ring, drain pipe, vent, and toilet bowl.

From DIY solutions to professional assistance, you need the best and bright ideas for that perfect toilet solution.

This article articulates the proper knowledge needed for your and your home’s peace and comfort about your toilet.

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