Giardia Diarrhea and IBS

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

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:

  • 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

  6. Sam says

    I got Giardia in 2009 in India, I carried it for about 6 months before diagnosis (mainly due to UK doctors being very disinterested). I dont experience extreme IBS symptoms, but it comes in bouts, not particularly painful, just uncomfortable and inconvenient. I think that these bouts do seem to relate to moments of emotional stress, changes (like moving house – as i am doing now…)

    This research sounds interesting! Could also be worth experimenting with reducing Lactose. Are there any other foods or things that are suggested to cause OR aid IBS symptoms?

    • says

      While I’m not a medical proffessional, or even a dietician, I HAVE read in lots of places that stress can set off IBS.

      If I were you, I’d seriously consider a food diary to see if there is a connection between something you’ve eaten and bowel trouble. I’ve read about all kinds of foods that can trigger IBS, so giving you a few in a list won’t help. It depends on YOUR system. Please see the food elimination diet page.

      I’ve read that it can take a few days for foods to cause problems, so looking back over the last few days, may be worth something. If your ready to take it to the next level, I’d consider a naturopathic doctor and/or dietician. They can usually help you find foods that may be giving you trouble. All the best, and good luck! Shawn

    • beezwings says

      I too had Guardia twice while in India, and have noticed strange digestive issues similar to yours in the years following, particularly when stressed or emotional. Recently, I have been trying to follow a low FODMAP diet because I think I may have fructose malabsorption (linked with IBS). Even after cutting out high-fructose foods such as onions, apples, coconut milk, and honey for just a few days, I’m feeling so much better.

  7. Misti Piette says

    I caught Giardia in Rome. I had it for a year and developed IBS-D and food allergies. I have been taking Triphalla and it seems to have really helped. It is suppose to help your body heal its entire Bowel system. I would also look into candida overgrouth as it can flourish in a giardia enviroment. I am hoping to clear up my food allergies as they seem to be what is now triggering my IBS.

  8. Alex says

    I got giardia a year and a half ago, it showed up in stool tests. Majority of my symptoms remain nausia, ill feeling gets to me the most never really had diarrhoea from it which puzzled the docs. Had for a few month before treatment. Stools, duodenal biopsy are negative now. Hope I get better in time. Also suffer from fatigue and burning skin which developed slowly after infection just hoping doesn’t get any worse.

    • says

      Alex, I sincerely hope things don’t get any worse too. If the giardia is gone, hopefully things won’t get any worse. I believe some people develop problems with foods after a gut infection. Is it possible that you have something like that going on? I have a page here about . And there is also info called . Maybe there are clues there you can use.

      Thanks for letting other people know about your experiences. May you get well soon! – Shawn

  9. Jodie says

    I was infected with Giardia about a year and a half ago in Guatemala. I think I only had it for a few weeks but the symptoms were chronic, I have never felt so ill.

    Since then I have a really low tolerance for alcohol, even a little makes me so sick the next day. Do you think it could be connected?

    • says

      I do think so. I’m biased because of my own experience, and don’t have science to prove it, but yes I think that alcohol and other bowel sensitivities can start after such an intestinal trauma.

  10. stresssedmum says

    My son, who was 2, caught giardia after going to the London to the winter wonderland in Hyde Park. He was eating some food and fell over on some soggy food wearing his gloves, He refused to take his gloves off and carried on eating. The next day he was throwing up, his belly was bloated, he was getting belly cramps and this carried on for 3 – 4 months. We took him to various Drs explaining what had happened and that we thought that that was the trigger. They all told us that it was highly unlikely. He developed a dairy and gluten intolerance, lost confidence in eating because every time he ate he was sick and lost a lot of weight. Thankfully we saw a consultant who asked us what we thought was wrong with him and listened to us and treated him with some powerful antibiotics that wiped out all of the bacteria in his gut. We were told it would take a year for him to get better. We have been back to the Dr a few more times this year because our son had started getting belly cramps and have been told there’s a chance he’s either got IBS or abdominal migraines. I, personally, think it’s most likely IBS. I really feel for him being so young and having something like this, be it ibs or the abdominal migraine, that can at times be debilitating. I am also furious with the Drs for not having listened to me and for not having taken a stool sample to test for this. I did request one but was told that I was not a Dr and to let them do their job. Giardia is absolutely horrible and I just wish that Drs would make this a routine test when people come to them. It can make a big difference if it is caught early. The ironic thing about when my son fell on the dirt was that my sister was laughing at me because I was stressed because I’d left my hand gel at home, not sure if it would’ve made a difference but can’t help wondering..

    • says

      That is HORRIBLE! There is NO pain like watching your child suffer.

      First let me say that I’ve looked into this, and it seems that alcohol based hand sanitizer would NOT have helped against Giardia has an outer shell that protects it from a lot of things.

      Did the consultant or anyone ever test for giardia??? You don’t mention it.

      The reason I ask is because (I’ve read) that giardia symptoms don’t show up until at LEAST 5 days after exposure. So while your son may have had giardia, it likely wouldn’t be from the glove incident. I got that info here :

      As far as still being sick, I wonder if the the powerful antibiotics you mentioned wiped out important bacteria that your son needs for a healthy gut, or if the original problem (giardia or not) still remains to a lesser degree.

      I talk a bit about helpful bacteria on the page.

      I’m looking more into the many kinds of bacteria in a healthy gut, and I hope to have more info on that soon.

      I hope something here helps you find some answers. – Shawn

    • anna says

      Hi, I am just wondering how is your son doing? My 2 year old daughter got this bug from day care. I got it later on from my daughter since them my and my daughter stomach neve returned to the normal.
      My daughter sinc then have loos stool with undugested food in stool as well losted weight. She also slowed dow with her development.
      Also developed food sensitivity. I recently stop working as I can not keep enything down.
      It just break my heart to see my daughter suffer like this.

  11. Christine says

    I visit Zambia 4 times a year…Iam from UK I had Giardia 5 times in one year and it was Chronic..I started taking MSM along with Allicin tablets..and I was Giardia free for over a year..seemingly the MSM puts a coating on your intestine which makes it slippy therefore the cysts..which have small suction cups at the end of their feet are unable to stick to yr intestine and get flushed out…anyway I now have IBS have tablets for that and have to get endoscope as bloods and stool samples came back clear…glad I saw this link on the Topix Forum that I joined when I got Giardia…. It all makes sense. Thankyou.

  12. Laura says

    My son was 16 when he caught Giardia in a cold Texas lake while in a class trying to get scuba certified. It was several months later when a doctor finally caught it and eradicated it with homeopathy. During that time, he developed stomach issues, lung issues, and allergies to wheat, corn, and dairy. It’s 2 1/2 years later and he is hoping to go away to college in a couple months. We have gotten used to the food changes, but the fatigue is still a big issue. It’s terrible and we don’t know what to do to make him better. Any ideas?

    • says

      Hi Laura, I am not a big believer in homeopathy. Naturopathy yes. I would take him to a regular doctor (I like osteopaths). There are treatments for persistent giardia infections. I hope it helps.

  13. Barbara Osorio says

    I was infected with Giardia in Chile while in early stages of pregnancy. My ob/gyn sent me to see an infectious specialist who thought it best not to treat me because of the pregnancy. “In 6 months time it will be out of your system anyway.” Testing after 6 months indeed showed that I was no longer infected but in the 6 years since I have developed IBS, Chronic Fatigue, and Fibromyalgia (in that order). I have suffered unrelenting fatigue and pain. Had to be on disability for 2 years, and then willed myself back to work part time, while still struggling with symptoms. I am fat, lactose, fructose, and carbohydrate intolerant. The FODMAP diet helps control the gas and bloating associated with the intolerances. Digestive enzymes and bile salts taken with meals also helps. I recently came across a very good website that I feel accurately describes IBS, and provides a comprehensive list of lifestyle and treatment options based on the results of research trials, including diet, physiotherapy, probiotics, and medications to resolve gut motility problems. I am hopeful that this regime will help improve my condition.

  14. Kim Valade says

    I have no idea where I got my giardia infection. But I had severe diarrhea for over a month (started in late feb. until April when I was treated) and many visits to the doctor with many stool samples, but no answers. I literally couldn’t leave the bathroom. My husband had to stay home from work to take care of our son who was 8 months old at the time. At one point, I went to the ER and the doctor gave me a super strong version of immodium because he just figured I had a viral gastroenteritis infection that would pass in 10-14 days. That little pill worked great! But then I ran out. And I was back to where I started. My doctor finally acted on a hunch. She thought maybe I had giardia because she had just treated a 10 yr old boy for it so it was on her mind. It was never confirmed by stool sample but she gave me the drug anyways. Within 48 hrs, I was feeling much better and by the end of the medication I wasn’t living in the bathroom anymore and could leave the house. But now I’m left with ongoing digestive problems. I still gave loose stools every day (1-5x per day), some cramping, lactose, caffeine and alcohol intolerance. I don’t absorb anything that I eat. It’s really discouraging. I would give anything to be constipated for a few days haha. I am currently taking a probiotic and some glutamine stuff from my naturopath. So far nothing is helping. The doctor did tell me that it can take many years for bowels to return to normal after a giardia infection. Now I’m just trying to figure out how to cope with it I guess

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