Why Does My Bathroom Smell Like Sewage?
A bathroom that smells like sewage means there is an issue with one of the drainage points in your bathroom.
This means that the sewage gases contained in the sewage system can freely seep into the air. These drains, including the toilet, are designed not to allow sewage gas into your home.
As professional plumbers, this question gets asked a lot.
We understand it’s not nice to get up in the morning and venture into your bathroom only to find that it stinks like sewage.
Everyone loves their bathroom, and many people take pride in maintaining a clean bathroom that smells nice and fresh.
But what happens when it doesn’t?
Unfortunately, even with the cleanest and most conscientious of homeowners, your bathroom can experience issues that are out of the reach of your average homeowner.
Plus, who wants that rotten eggs smell in their home?
Luckily there are simple fixes for a few of these problems, and your average DIY homeowner can be up and running with a nice and clean bathroom in no time.
Here are the most common causes of that bathroom sewer smell and how to eliminate that sewage odor.
1. Dirty or Dry P-Trap

Dirty or dry P traps are the most common cause of a sewer smell in your bathroom or toilet.
The P trap is a u shaped pipe located at the back of your toilet and is fitted to all sinks and drains.
It traps water to form a barrier between the air in your bathroom and the sewage gases.
If you don’t use any of these regularly, the water in the p trap can evaporate, leaving your bathroom with that foul odor.
🧰 The Fix!
The most common problem has the easiest fix. Run water into the offending drain to fill up the p trap, and the problem should disappear.
You can also run a cleaning mixture such as bleach or baking soda to remove any build-up.
Related Reading: What Is a P Trap and How Does It Work?
2. Clogged Shower Drains

Hopefully, everyone in your family showers regularly.
After a while, pieces of dead skin, soap, gels, hair and all sorts of stuff can clog your shower drain.
If you think your shower is suffering from that dreaded sewer smell and is not draining correctly, you probably have a clogged drain.
🧰 The Fix!
Another easy one for the DIYer can be a little disgusting, depending on what’s stuck in your drain.
Every husband I know loves pulling a mixture of his wife’s hair and other gunk out of a shower drain.
First, pop off the shower drain cover and pull out any debris that is accessible.
If it looks significant, you can use a plumbers snake or auger to remove the gunk.
Next, use a drain brush for that disgusting biofilm that forms around drains.
Then pour a mixture of boiling water and vinegar slowly into the drain.
Once complete, add 1 cup of baking soda and let it sit for about 2 hours. Then flush with hot water.
Related Reading: Got a Smelly Shower Drain? Your DIY Fix It Guide!
3. Damaged Toilet

The toilet itself can be a source of sewer odors.
Wear and tear over time and knocks against it can cause sewer gas leakage.
Also, if it’s a toilet in a part of your home that doesn’t get used that often, the p trap could be suffering from the same problem.
Another major problem is the wax ring sealing or caulking at the toilet’s base.
This can come loose, causing gas to escape.
Also, cracks in the toilet bowl can cause moisture to build up and invite bacteria to the party, which could also cause foul odors.
🧰 The Fix!
If it’s the P trap, follow the same guidelines above for your toilet.
If it’s a broken seal around the base, you can easily reseal or recaulk it though this may be masking a bigger problem.
If you have a major leak, you will know about it. Some caulking is not going to mask that.
✅ PRO TIP: Don’t forget to leave a small section open at the back for moisture leakage when caulking.
The smell might come from where the toilet seals to the drain pipes.
If this is the case, it requires the removal of the toilet, which is best left to your local plumber.
Want to learn more about whether to caulk or not, check out this article: Should You Caulk Around a Toilet?
4. Gurgling or Bubbling Toilet

A bubbling or gurgling toilet is never a good sign.
A range of problems can cause this and is best left to the professionals.
Gurgling sounds are the result of negative air pressure in the plumbing system.
This is due to a blockage somewhere in the sewer system.
We have a great article dedicated to this problem, and you can learn more about it here: Toilet Gurgling? Your Quick Fix It Guide!
🧰 The Fix!
Follow the troubleshooting process in the article listed above.
It will probably require a sewer inspection with a sewer scope if it’s more serious than a clog in the toilet bowl.
5. Clogged Drains

Drains can suffer the same fate as your shower drain.
Though it’s less susceptible to stuff that comes off you in the shower, it can also get clogged.
Maybe you have kids that love to stick things down drains, or there’s a build-up of toothpaste and other gunk.
🧰 The Fix!
Check out this article on how to fix a slow-draining sink. How to Fix a Slow Draining Sink.
The process is similar to how you would fix a clogged shower drain.
6. Clogged Plumbing Vent

The vent pipe is how your home’s plumbing system breathes.
If it gets blocked, the sewer gases will backup into your system and make your bathroom smell like hot garbage.
No air fresheners in the world will be able to mask this smell. Gurgling toilets are a clear giveaway for this problem.
🧰 The Fix!
We covered this in our article on gurgling toilets, so feel free to check that out.
Here’s the link again: Toilet Gurgling? Your Quick Fix It Guide!
7. Bacteria Build Up

As I’m sure you know, your home sewer system is the perfect place for bacteria to grow.
So if you have any of the problems listed in this article, these can pave the way for the bacteria associated with the smell to make their way into your bathroom, especially in hot weather.
🧰 The Fix!
Bleach is a great way to kill these bugs.
Keeping your drains and toilet clean with a bleach solution can greatly reduce bacterial growth.
Pour some bleach into your toilet’s top tank and give your toilet bowl a good scrub that can help with the bad bathroom smells.
Related Reading: Is Toilet Water Clean?, and Help! My Bathroom Smells Musty. What Should I Do?
8. Sewer Backups

If you notice a strong sewage smell after heavy rainfall, it’s most likely caused by a sewer backup.
When it rains heavily, the excess stormwater puts pressure on your municipality sewerage system, which can cause backflow from the main line and into your home’s drain lines.
If the water pressure is not high enough to flood your home, it can be high enough to push sewage smells back into your home, causing that foul smell.
🧰 The Fix!
If this is the problem, it’s out of the average homeowner’s hands.
This is a problem for the city to fix if it’s a continuing problem during heavy rains.
If it’s just gas making its way into your home, it’s best to wait it out.
If it’s a continuing problem, install a backflow valve in your sewer lines to prevent future backflow.
This will require a call to your local professional plumber.
Related Reading: How to Find the Main Sewer Line in Your House
9. Full Septic Tank

If you live away from the city and are not connected to the municipal sewer system, you probably have a septic tank.
When your tank or leach field becomes full, you may notice the smell and the associated gurgling or bubbling sounds coming from your toilet.
Your toilet will also struggle to flush correctly.
Related Reading: Does Every House Have a Septic Tank?
🧰 The Fix!
Empty it! This is a simple fix. It’s good practice to regularly check the levels of your septic tank to ensure this doesn’t happen.
✅ PRO TIP: Add a calendar reminder to check it out at times, depending on your usage level. A larger family will require a more regular inspection.
⭐ Can Sewer Gases Make You Sick?
Sewer gases can pose a health risk if left untreated. This gas can be a mixture of hydrogen sulfide and methane gases.
Not only is it flammable, but it can also cause health problems if not dealt with promptly.
📗 Related Reading: What Does Sulfur Smell Like? A Homeowners Plumbing Guide
⭐ When to Call a Professional Plumber

Everyone loves a clean bathroom. However, it’s always a downer when you encounter an unpleasant smell in your home’s bathroom.
At best, it smells disgusting; at worst, your house could get flooded with sewage which is a major health hazard.
If you followed the steps outlined in this article and still have problems, it’s time to call in the cavalry or a professional plumber.
Don’t know who to call? Check out if Phyxter Home Services is in your area and get a quote from the best local and independent plumbing contractors in your area.
We’re always happy to help, so contact us to find out how we can!
If you live in the Okanagan Valley region, give Phyxter Plumbing Services a call, we are more than happy to come and check out any of your plumbing system issues.
Related Reading: DIY Guide to 15 Common Plumbing Problems & Solutions