Giardia Diarrhea and IBS

Find out how the giardia parasite might cause you permanent damage!

Giardia parasites
They’re almost pretty aren’t they? Until they are inside your intestines where giardia can cause intense IBS symptoms and may cause long term damage.
© Can Stock Photo

Giardia diarrhea is caused by a parasite called giardia intestinalis, or giardia lamblia.

Recent studies show that people who get a giardia infection can later develop chronic bowel symptoms, such as diarrhea, constipation, cramps, etc.  Sound familiar?

I wrote on another page about how certain kinds of infections can lead to IBS, but I wanted to cover this little beastie, because I think this is how I got irritable bowel syndrome.

What is a giardia infection?

A giardia infection is called giardiasis by doctors. It used to be called beaver fever, because it was believed that beavers were the transmitters of the disease.

As it turns out many animals can transmit a giardia infection (for instance, dogs can get it). Humans usually get it by drinking or otherwise swallowing contaminated water (like brushing your teeth with the water from a stream, like I did).

Giardiasis symptoms:

Many people can get the parasite and have no symtoms, for others, the symptoms usually show up after about two weeks.

The main symptoms of giardia are intense watery stool and bowel cramps, that can come and go for a few weeks. Here’s the full list of common symptoms:

Giardia symptom list:

  • Young blonde woman with diarrhea from giardia lamblia.
    A few days after hiking the beautiful trails, and being exposed to contaminated water, giardia diarrhea strikes!
    © Can Stock Photo

    Watery stool that may have a horrible smell

  • Abdominal cramps
  • Bloated belly
  • Feeling tired (fatigue)
  • Nausea
  • Weight loss

Hmm. Those sound a lot like IBS symptoms. And yes giardia diarrhea smells particularly nasty. Sorry to mention it, but I thought you should know, if that’s what is happening to you.

How giardia leads to IBS:

This isn’t really known, but it is thought that, like other infections, giardia causes changes to the way the nerves of the bowels work. Somehow this leads to visceral hypersensitivity, bowel cramps, diarrhea, bowel spasms, trapped gas, and constipation.

In other words giardia can lead to chronic IBS symptoms.

Research into how it actually happens is ongoing.

Giardia treatment:

I never got my giardia diarrhea treated. I didn’t know how serious it was.  Treatment is simple, and I’m sorry I didn’t have it.  Don’t make my mistake.

The standard treatment for giardiasis is a prescription for antibiotic medicine. The commonly used antibiotic for this parasite is Metronidazole (I have no idea how to pronounce THAT :).

When to see a doctor:

If I were you, and I thought I had giardiasis, I’d seek treatment right away.

If you don’t have IBS, you might get it. And who knows, it might make your IBS worse if you already have it.

Whether you think you have a giardia infection or not, you shouldn’t go more than a week with the symptoms mentioned above (at least in my amateur opinion).

You can get dehydrated or have other complications.

Get help if you need it, even if it means talking about your bathroom problems!

What about you? did you ever have giardiasis?

Do you think it led to your IBS symptoms?

Let people know in the comments section below!



  1. P hancock says

    My son and I had giardia, probably from the baby pool of our neighborhood pool. We both have stomach issues often. We were treated for giardia at the time, yet we still suffer ongoing stomach problems after eating. Bloating, discomfort, diarrhea. Can we be retreated with the antibiotic?

    • says

      I would think the first thing to do is to check for a giardia infection. Your doctor would have to decide if antibiotics are required. Sorry I couldn’t answer you question one way or the other.

  2. Ben says

    I was treated for a giardia infection 20 years ago at the age of 6. Ever since, I have had chronic IBS. 20 years later and it persists!

  3. vicki says

    Six years ago I got guardian from grand daughter who most likely caught it kindergarten. I have been lactose intolerant ever since but not the child. I have ibd symptoms and am convinced that it damaged the villi and ability to make many enzymes. I am now 18 pounds underweight and also developed allergies. Albendazole is better to take according to the doctor. Tests did not prove giardia. It is gard to see in tests. I also had cdiff which can also damage the colon and some similar symptoms. Anyone’ if you think you might have this evil parasite get help asap. There is now some report Online of guardian not getting better due to mala sorption of oral mess and treatment needed by iv.

  4. iamkinghenry says

    I got chronic giardia and had it for like 2 years before treatment. It’s been 8 months after treatment and my bowels are still messed up. I had O&P samples tested at 3 & 6 months that were negative after treatment so it looks like my system is damaged. I guess only time will tell if it returns to normal.

    I think I got it simply by wiping my hand across my mouth after getting it wet by playing fetch in a stream with my dogs.

    • says

      Something so small, you can’t see it. In a passing droplet of water. And yet all the misery this can cause. I hope time is kind, and you get some relief.

  5. says

    I had ibs most of my life. For some reason it stopped about 12 years ago. After a recent bout of giardia it has returned. I was treated for the giardia and those test are now showing neg for the bug. I am not looking forward to ibs again or being told to just eat more fiber and it should clear up. I hope the treatments for ibs have improved.

    • says

      THAT SUCKS. After 12 years, you’d think a person would be safe. I can’t say I’ve seen many improvements in care, but that’s just from the outside looking in. Maybe the doctors have something up their sleeves. So far I haven’t seen much of that though. That doesn’t mean you can’t find the right person to get you fixed up! Good luck! – Shawn

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