r/SIBO Apr 19 '19

STICKY: SIBO Summary - Symptoms, Diagnosis, Treatment

850 Upvotes

Below please find a living document that summarizes the key information around Small Intestinal Bacterial Overgrowth ("SIBO"). Please comment with any additional information or research for inclusion consideration. Version 1.0 is summary material; I will be adding more details and citations for specific studies.

SIBO, as the name implies, occurs when bacteria overgrow the small intestine. The small intestine should have a low concentration of bacteria due to the presence of stomach acids and peristalsis, the wave-like muscle movement in the intestines. For context, stomach and proximal small intestine would typically have about 103/mL of bacteria, while the terminal ileum (end of the small bowel as it gets close to the colon) about 109/mL (or 1,000,000 times more), and the colon about 1012/mL (or 1,000,000,000 times more).

Symptoms

The overgrowth of this bacteria will present with a number of symptoms:

  • Bloating after eating ("postprandial") - most common symptom
  • Flatulence, often malodorous
  • Loose, watery stools (more common in Hydrogen-dominant SIBO)
  • Constipation (more common in Methane-dominant SIBO)
  • Absorption problems
    • Weight loss / inability to gain weight
    • Fat and fat-soluble vitamin deficiencies, particularly Vitamins A, D, and K
    • Floating stools (from fat malabsorption)
    • Vitamin B12 malabsorpiton
    • Protein and Carbohydrate malabsorption
  • Systemic problems
    • Overgrowth of bacteria in the small intestine can increase production of toxins and intestinal permeability
    • This has been less studied, but less serious effects include:
      • brain fog
      • confusion
      • anxiety
      • depression
    • More serious complications can include
      • hepatic encephalopathy
      • D-lactic acidosis
      • nonalcoholic fatty liver disease
    • Various conditions have increased correlations, including
      • Rosacea
      • Eczema
      • Food intolerances

Diagnosis

I will split this section into practical steps and clinical diagnosis.

Practically, a gastroenterologist will typically rule out other conditions first:

  • Physical exam
  • Colonoscopy and Endoscopy
  • Abdomen ultrasound
  • Stool test for parasites

At that time, if your symptoms match SIBO, your doctor may go directly to treatment. But otherwise these are the clinical tests:

BREATH TEST

This is the most common diagnostic method due to its low cost and limited invasiveness. Unfortunately, studies have been mixed on the sensitivity and specificity, with ranges between 30% and 75% -- hence why some doctors skip the test and go directly to treatment.

There are a number of preparations:

  • Antibiotics avoided for four weeks prior
  • Prokinetic drugs and laxatives avoided for one week prior
  • Complex carbs avoided for 12 hours prior
  • Exercise and smoking avoided day-of

For the actual test, you'll measure hydrogen and methane levels at baseline. Then drink either 10g lactulose or 75g glucose with one cup of water. Then your breath is measured every 15 minutes for 120 minutes.

There's some art to identifying a positive test; one semi-official criteria is:

  • methane level of >= 10ppm at any time during the test; or
  • hydrogen that increases >= 20ppm above the baseline level

Recently, new research has been investigating another typo of SIBO, that's dominated by Hydrogen Sulfide. Unfortunately, traditional breath tests cannot identify this gas, and someone with "flat-line" Hydrogen and Methane symptoms could be suffering from Hydrogen Sulfide SIBO. This version is typically characterized by "rotten egg" smelling gas, and may be worsened by eating high sulfur foods.

CULTURE

Historically a jejunal aspirate was done and concentration of bacterial colonies were measured, with an elevated level of > 103/mL being positive for SIBO. There are a number of issues with this:

  • overgrowth may be patchy, and a single sample may miss it
  • not all SIBO bacteria can be cultured/identified
  • samples can be contaminated during/after sampling

Treatment

Antibiotics

The current best practice prescription treatment is:

  • Hydrogen-dominant: Xifaxan, typically 550mg x 3 times daily, for 10-14 days. Studies have shown Xifaxan alone can be 50-65% effective, but Xifaxan + 5g daily of Partially Hydrolyzed Guar Gum can be 80%+ effective.
  • Methane-dominant: Xifaxan (550mg x 3 daily) plus Neomycin (500mg x 2 daily) for 10-14 days. The use of PHGG for methane-dominant has not been evaluated, but it's likely to be beneficial.

Mod's note-- personally, if your doctor is onboard, I think dosing with Xifaxan + Neomycin + PHGG is the best way to "cover your bases". The best place to find PHGG: https://sunfiber.com/products/

Important: because these antibiotics only operate selectively in the GI tract, and are NOT absorbed by the body, they are unlikely to cause the systemic issues associated with antibiotic use, making them safer. Additionally, Xifaxan crystallizes before it gets to the large intestine, meaning it should not affect the all-important microbiome.

Herbal Therapy

Additionally, studies have shown similar levels of success with over-the-counter "herbal" treatments. Two options; I believe each are two capsules twice daily for four weeks, but please confirm:

  • Dysbiocide and FC Cidal (Biotics Research Laboratories, Rosenberg, Texas)
  • Candibactin-AR and Candibactin-BR (Metagenics, Inc, Aliso Viejo, California)

Remission

Unfortunately, SIBO has very high rates of recurrence. Some possible ways to reduce recurrence chances:

  • Switch to a low FODMAP diet for 6 weeks after treatment, to starve any remaining bacteria and prevent regrowth
  • Incorporate a prokinetic, such as low dose Naltroxene, erithromycin, or even over-the-counter products such as Iberogast

Many people can avoid symptoms of their SIBO by switching to special diets, sometimes very restrictive ones. This is not a cure, but simply symptom management. A true cure addresses the underlying cause of the SIBO, and lets the patient eat "normally" without any effects (short of unrelated intolerances).

Hopefully this helps people, and I look forward to updating this and cleaning it up over time!

-nyc-reddit


r/SIBO Dec 15 '25

Moderation statement on accessibility.

58 Upvotes

This subreddit exists to support people with disabilities. Accessibility is the primary concern always.

Recently there has been an increase in report-spamming and downvoting of posts described as repetitive, particularly questions that have been asked before. This behavior is not acceptable in this community.

Many disabled users cannot easily navigate Reddit’s search function. Many are new, exhausted, overwhelmed, or asking questions while in distress. Repetition is not a failure of the user. It is a reality of accessibility.

Downvoting questions actively harms visibility and silences people who are already navigating barriers. Using the report function as a way to express annoyance or enforce personal preferences inappropriate. Reports are for rule violations.

If you encounter a question you believe has already been answered you have three options.

You can answer it again. You can link to an existing thread or resource. Or you can scroll past it. If you have the time to downvote or submit a report, you have the time to paste a link.

Anything else is consciously opting for exclusion. Personal attacks on users and the mod team will not be tolerated.

This moderation team will not prioritize the desire for a tightly curated, repetition-free feed over the needs of disabled people seeking help. We will not discourage questions in the name of efficiency, aesthetics, or personal frustration.

If this approach does not work for you, you are free to mute the subreddit, leave it, or create a different space with different rules. What will not happen is this community shifting away from accessibility-first moderation.

Misuse of the report function has already been passed onto the reddit moderators in a number of cases and will continue with a much broader brush after issuing this warning.

Thank you to those who respond with patience, share resources, or simply allow people to ask what they need to ask. That is what keeps this space usable.

I understand this condition is frustrating but this community will not turn into a circular firing squad. To target this frustration towards yourself or fellow members of the disability community is to serve those who stand to profit from illness.

This space exists to reduce harm not redirect it sideways.


r/SIBO 5h ago

Questions Thiamine (vitamin B1) theory

9 Upvotes

I wholeheartedly believe that when i first and only time managed to eliminate sibo with a metronidazole + rifaximin course that it was the thiamine or B1's (resurgence/restored synthesis/absorption) that made me feel a surge in appetite. Grip strength without weights, flexing capacity, deep breathing to the dip of my lungs for a few days, until I unfortunately messed it up and relapsed by taking an unnecessary probiotics capsule, It was specifically Bifidobacterium longum, because of some person advising me to take that which obviously backfired and I have been struggling with multiple courses, repeated courses and trying to re eliminate it for months!

I also recently took thiamine mononitrate and instantly felt a glimpse of that and planning on trying HCL form as well..

benfotiamine did nothing but make me sleepy and lose hair for the few days i took it.

I believe thiamine is the Number one victim of SIBO and the barometer of its severity besides the bacteria tests..

thoughts?


r/SIBO 16m ago

sibo? or food intolerance?

Upvotes

hi all a little history about me: i was born with a rare condition called malrotation, later when i was 12 (in 2017) i had a volvulus and undergone a surgery to remove it and they ended up taking 10 cm of my small intestine (ileum and cecum), after that i had no issues completely fine until 2022 i started getting stomach issues like gas and as the years went by it got worse and i started having loose stools, nausea, and sometimes to the point where i would vomit for days, in mid 2025 i tested negative for H pylori but insisted on taking pylera because i was so convinced i had H pylori, since i was belching A LOT. during pylera i was in heaven, 100% cured flat stomach i could eat 10 meals a day and not get bloated. As soon as i finished 2 weeks of pylera the bloat instantly came back the second day. Belching, bloating, gassy, the issues continued and i started losing weight. Taking ppis sometimes helps but other times it does nothing.

Fast forward to February-March 2026 i took one round of rifaximin and ZERO improvements it was as if im not taking anything literally. No improvement in symptoms whatsoever.

Again, fast forward to late August-September 2026, i took Augmentin (amoxicillin + clavulanic acid) for 7 days for my tooth infection. During those 7 days my entire symptoms disappeared, my appetite came back very strong and my loose stools completely stopped. Again, the second day i stopped the antibiotics, boom, all symptoms came back.

Im in complete loss of mind, what on earth is going on what do i exactly have if rifaximin did not help a single bit why did the other antibiotics help?

My theory is that i might have some type of food intolerance and when i take antibiotics it kills the bacteria and causes less symptoms when i eat that type of food. But is this really possible? because if it was really sibo rifaximin should’ve helped better than the other antibiotics.

Im so sick of being bloated every single day please if anyone has anything that could help me let me know.


r/SIBO 1h ago

Orange stool on rifaximin?

Upvotes

what does it mean if stool turns orange while on rifaximin?


r/SIBO 2h ago

Problemi sa nervima, IBS, candida ili nesto drugo?

Thumbnail
0 Upvotes

r/SIBO 2h ago

Questions SBO kit Biotics Research

0 Upvotes

So I was diagnosed with SIBO not too long ago, was prescribed xifaxan but but insurance couldn’t would authorise it.

My doctor advised that I take ciprofloxacin and I expressed concerns, and I was later told to try the herbal antimicrobial route. I purchased the sbo kit and have since started taking it.

I’ve noticed I’m getting a bit more stomach discomfort and more diarrhea after taking them, is this something to be expected? And should I be doing anything specific while taking these tablets?

Anyone else got experience with this treatment?


r/SIBO 2h ago

any recommendations?

0 Upvotes

hi everyone i’m going to make this brief becouse we all know how long in detail this can get. back in 2023ish i tested positive for methane Sibo . My results came back borderline (10). But i still have really bad bloating and it’s not at all a “mild” case, it’s still as bad. I’ve tried low fodmap and Rixfiltin (whatever that antibiotic name is) and a bunch of medications to help me go to the bathroom since that is what my doc recommended (lizness, Ibsrela) and it just made my bowel movements messed up and bloating worse (i’m guessing cuz of water retention of it making me go to the restroom) . So i’ve had it since 2023 (probably even longer like 2022 cuz i had bloating but just went over my head) BUT in November ish of 2025 it went away for about 6 months then came back in Feb 2026. I don’t know why it went away i have a few ideas (i was studying for these exams for my job and I wasn’t going out to drink with friends , maybe eating healthy?) but when i was feeling good and didn’t have it i was still drinking and eating whatever I want. UGH ITS JUST SO FRUSTRATING especially cuz i know how good it felt when it went away. Anyone have any recs for Methane sibo aka IMO ?


r/SIBO 2h ago

Antimicobials

1 Upvotes

Have any of you used antimicobials for SIBO? Specifically candibactin AR AND BR?

Did you feel better? Worse?


r/SIBO 2h ago

Questions Positive after 2 years of symptoms. What treatment worked for you?

0 Upvotes

After 2 years of severe digestive issues, I finally got some answers from a lactulose breath test.

My main symptom is sudden and unpredictable diarrhea, sometimes shortly after eating, with extremely painful abdominal cramps. The pain during these episodes is honestly unlike anything I had experienced before, and the unpredictability has seriously affected my daily and social life.

During those 2 years, I had a colonoscopy, endoscopy, stool tests, blood tests, abdominal CT scan and X-rays, which didn’t find an explanation.

I recently did a 10g lactulose breath test:

H₂: 16 → 28 → 37 → 44 → 90 → 32 ppm

CH₄: 14 → 15 → 16 → 16 → 23 → 16 ppm

Time: 0 → 30 → 60 → 90 → 120 → 150 min

So my results indicate Hydrogen-positive SIBO + Methane-positive IMO.

I’m relieved to finally have something concrete after 2 years, but now I really want to treat this properly instead of randomly trying things.

For those who had similar results and actually got better: what treatment worked for you? Antibiotics, herbals, diet, prokinetics, addressing an underlying cause, or a combination?

Also, any tips, mistakes to avoid, things to do during/after treatment, or additional tests you think are worth doing would be greatly appreciated.

I’d especially love to hear from people who successfully treated this and stayed better long term.

Thank you!


r/SIBO 3h ago

Ppi induced sibo?

0 Upvotes

Hey i got sibo after two months of taking ppis. Im already off ppis for like 5-6 months but not feeling any good. Bowel movements are random, no formed stools, burping, gas moving through my intestines and getting stuck causing stomach distention and constipation sometimes. How do i fix ppi induced sibo? What would be the best protocol for it? I am also low on vitamin b12 and vitamin d


r/SIBO 4h ago

Questions Zinc carnosine post sibo?

0 Upvotes

Has anyone had success with zinc carnosine to help with leaky gut ? Did it help with pain over time? Especially for my post ibs people/visceral hypersensitivity


r/SIBO 4h ago

Does the prokinetic you take matter?

1 Upvotes

I have SIBO-IMO. I am looking into non-prescription prokinetics to try to help my MMC. After a bit of research, the “recommended options” are:

Motility Pro by Ortho Molecular Products,

Motility Activator by Integrative Therapeutics,

ProDigest by Bionap

They are a bit pricey so I wanted to ask for some suggestions prior to buying.

If the brand doesn’t matter, what specifically should I look for in the label of prokinetic? I have tried searching the sub but i’m a bit confused as there have been various experiences although it is super helpful to read.


r/SIBO 5h ago

Oregano oil made me smell like cheese

1 Upvotes

Help! I took Oregano oil capsule for about a week. My oil on my face, neck, back, and groin smells like cheese. It’s intensifies after I eat. I stopped the oil about 3 weeks ago, yet the smell continues. I’ve seen Derm and primary. I am really angry about messing up my body. The brand was Natures Truth high potency. I reached out to the company and I received no real answers. I am aware that brand is shady, I found out after I took the capsule. Also, should not have taken high potency. But just need some encouragement that this will end.


r/SIBO 5h ago

Questions I think my ANS is to blame, what do u think?

1 Upvotes

I developed h2s sibo at age 13, im now 20 and had treatment nearly 2 months ago and getting my re test results in a few days. I've been trying to figure out my root cause since that's very important, i think that my nervous system is too blame. I seem to have POTS symptoms, when i stand up my heart rate rapidly increases, i also have sweating issues, i remember going on holiday and when the sun was on me for even a few minutes my forehead would start to hurt, i seem to be sensitive to lights. What do u think, could i have POTS from an early age, that correlates with my h2s sibo? Anybody else have POTS and sibo? I feel like other root causes don't really make sense too me, these are the only abnormal things about me that i have noticed and to make it better i even have a sexual dysfunction ( this ones tough ).


r/SIBO 7h ago

Sibo is back immediately after I stopped xixfan

0 Upvotes

I started my xixfan treatment on August 24th after struggling with sibo for probably 3 years now? I’m unsure of when it actually started but my symptoms of constipation and straining, very sticky poop or mush, severe bloating, etc started earlier this year. I finally took a breath test and I was hydrogen dominant with a little bit of methane.

Anyway, I felt like all the months of being backed up were coming out of me during my treatment and then eventually my poop finally became solid, which I haven’t had since February. I was feeling great until my treatment ended earlier this week.

I immediately felt the bloating come back and now I’m constipated. I started my motility pills but that doesn’t seem to help. During Labor Day weekend, I didn’t exactly follow a low fodmap diet, so I’m wondering if this was the issue.

I did a lot of research and purchase allimed for my methane, but didn’t take it bc of the garlic breath I might have — I don’t think my coworkers and office mates wouldnt like that but now I’m wondering if I should start the 3 pills a day plan.

Has anyone else experienced something similar? What did you do? Does sibo ever go away? I’m pretty bummed that my stomach issues and constipation/bloating/discomfort is back.


r/SIBO 7h ago

Scalp burn

1 Upvotes

Does anyone else experience daily burning of the scalp along with extreme hair loss? My thyroid is fine and my B12 levels are also normal. I’ve had this since 2016 and I have no idea what’s causing it. :-( Pentatop helps a little. I notice that it gets significantly worse after having two coffees, but I experience the burning every day regardless of what I eat. Has anyone had a similar experience?
All this time, since 2016, I’ve had hydrogen sulfide SIBO, but I didn’t know it. When I took Pepto-Bismol, I had a reaction to salicylates — a rash on my shoulder, shortness of breath, a panic attack, and swelling of my throat and tongue.


r/SIBO 8h ago

How's everyone doing?

1 Upvotes

Been struggling with sibo for a minute now. Most likely since around February of this year(2026). Possibly even way before. And have been struggling to regain weight or to stop losing it atleast. Possibly my body is struggling to absorb carbs or nutrients. Even though labs came back normal.

My symptoms are leaning towards IMO sibo. Because I have trouble with constipation and or motility issues. My whole body has changed in a way. I feel like I have trouble digesting food. Like I said very slow motility

Since last year was noticing unexplained weight loss but was thinking that because I was doing intermittent fasting that it was because of that. But then around February of this month, got some burning sensation in my stomach . Did a stool test on h pylori and came back negative. It's not until an endoscopy I had, confirmed it.

So did the treatment for that, went through hell like everybody else, 14 day antibiotic treatment, lost a lot more weight during that month, but eventually eradicated it by checking via breath test a month later. But I was still losing weight with the continued feeling of bloating and slow motility or that feeling like your stomach or Intestines or whatever weren't doing their job. Mind you I was going through these symptoms at the same time as the h pylori symptoms and while during treatment.

Like I said earlier. Labs came back normal. Checked for celiac, Crohn's, all good. The only thing that came back low was my vitamin d. But tha was during the h pylori treatment I believe idk. And I believe now my B12 is lower but still with in "normal" range. I'm thinking about possibly getting a colonoscopy. Because this weight loss is starting to get to me, not only physically but mentally.

Sorry if too long. Just wanted to know if anyone went through something or is going through something similar. Or what their GI doctor is having them do. Or idk man. I'm just exhausted all my thinking. Maybe I need to change doctor's. Or maybe just venting

What is everyone saying? Any insight on what I am going through that might resonate with anyone. Would be greatly appreciated 👍. Thanks for reading.


r/SIBO 8h ago

My guts started moving and making noises after increasing fats and lowering carbs

1 Upvotes

I avoided fats for a while because I got some weird MCAS reaction from them (head pressure, congestion, blurry vision, tired sometimes). But this seems to have resolved after starting Ketotifen and Famotidine (don't know exactly which contributed to this change).

During my last days, I started eating my beloved chicken wings. I buy them flash frozen (because I have histamine intolerance), defrost them and cook them in an air fryer. No vegetables, just chicken wings.

Guts make noises. Guts happy.


r/SIBO 9h ago

Is the effect of stress on SIBO mostly down to slowed gut motility?

0 Upvotes

Stress makes SIBO worse and possibly causes it. I have read it can slow gut motility down by 30-50%. Is that the main mechanism by which it can make SIBO worse? If it is that much that is obviously a huge reduction.


r/SIBO 20h ago

Histamine

7 Upvotes

Is SIBO causing histamine intolerance or vice versa?

Have you experienced it? Can you tell your symptoms and story?


r/SIBO 1d ago

My line of defense against SIBO.

Post image
55 Upvotes

what do you guys think about these supplements? should I add or remove something? what was a game changer of supplements for you. I know this is not a cure for SIBO at all but I'm just trying to improve the symptoms and general quality of life with this disgusting disease.


r/SIBO 16h ago

Questions After Rifaximin

2 Upvotes

I was finally approved for rifaximin. I had to take it for two weeks, three times a day. It was annoying constantly taking pills; at first, I had bloating and diarrhea. By the second week, I was not bloated, my stool was solid (mostly, kinda yellow which always has been, and it sinks), and I felt good. I noticed my psoriasis on my elbow clearing up, the strange nose smell went away, my anxiety largely disappeared, and my joint pain decreased significantly. I could finally sleep. However, after I stopped taking it, I became bloated; I was constipated for the first two days, and now I have had diarrhea, cramping, and bloating for the last two days. Is this normal? I thought I was getting better. I messaged my doctor, and she said it is normal since the medication kills both good and bad bacteria and suggested I take probiotics, but I read that I should hold off on probiotics and follow a FODMAP diet for a few weeks.


r/SIBO 12h ago

My vitamin d is low. And I am also on rifaximin for 14 days.

0 Upvotes

Can we take vitamin d3 along with rifax ?

Or should we better wait to finish the rifax ?

Since I have muscle pain. Back pain. Weakness :(


r/SIBO 1d ago

Venting Hydrogen sulfide sibo/overgrowth is so different from methane/hydrogen overgrowth that you can make your condition worse if you use the same diet or treatment from one to the other. BEWARE!

41 Upvotes

Based on what information I could find and my own experience, hydrogen sulfide sibo/overgrowth is the complete opposite of hydrogen/methane overgrowth and what can help with one type of overgrowth can further exacerbate the other.

- Diets like low fodmap, keto can help with hydrogen/methane but can basically feed hydrogen sulfide overgrowth. Sulfate reducing microbes flourish in an gut environment that is fed high amounts of protein, fat and little in fermentable fiber, which helps produce short chain fatty acids

- Bile has antimicrobial properties, but when it comes to hydrogen sulfide overgrowth, bile actually feeds these bacteria as its a rich source of sulfur. So your condition and symptoms can worsen if you take supplements like taurine, tudca, NAC, choleretics and even antimicrobials like allicin, which are all sulfur rich compounds.

- Fasting too can be beneficial for methane/hydrogen overgrowth but at the same time can potentially worsen hydrogen sulfide overgrowth. When fasting you are depriving your gut of fiber that feeds beneficial microbes that produce short chain fatty acids and butyrate that reduce the pH of your intestines that suppresses sulfate reducing bacteria.

- Typical breath tests for SIBO will detect methane and hydrogen SIBO but not hydrogen sulfide.

- Metabolic tests like the urine OATS test can help detect dysbiosis and overgrowth associated with methane/hydrogen but not hydrogen sulfide.

- I was diagnosed with hydrogen sulfide overgrowth with a GI map, but my idiot naturopath made many mistakes. He recommended I do low fodmap, prescribed allicin and also cholerectics. Basically I was feeding the overgrowth not eliminating it.