What Are the Symptoms of SIBO? Understanding Methane vs. Hydrogen Symptoms

When it comes to gut health, few things are as frustrating and elusive as Small Intestinal Bacterial Overgrowth (SIBO). And if you’re reading this, you might be wondering if your digestive symptoms could be linked to SIBO. So let’s break down what it is, how it forms, and how symptoms can vary depending on whether you’re dealing with methane or hydrogen-dominant SIBO. Plus, I’ll be sharing some of my own symptoms and experiences to help you feel a little less alone on this wild journey.

What is SIBO?

SIBO stands for Small Intestinal Bacterial Overgrowth. It’s when bacteria that are normally found in the large intestine decide to party a little too hard in your small intestine, where they definitely do not belong. The result? Fermentation of food that leads to all sorts of uncomfortable symptoms.

SIBO can be caused by many things, including a history of food poisoning, sluggish motility, adhesions from surgery, thyroid imbalances, vagus nerve dysfunction, and even chronic stress. The small intestine just isn’t designed to handle bacteria in large quantities, so when they overgrow, it’s a recipe for disaster.

Symptoms of SIBO: Methane vs. Hydrogen Dominant

It’s important to know that SIBO symptoms can differ based on whether you have methane-dominant SIBO, hydrogen-dominant SIBO, or even hydrogen sulfide SIBO (which is less common but still worth mentioning).

Methane-Dominant SIBO (IMO - Intestinal Methanogen Overgrowth)

• Constipation (This is a big one. Methane-producing archaea are known to slow motility.)
• Bloating and distention (especially after eating anything that ferments quickly like carbs or fiber)
• Belching (because methane likes to make an appearance all the way up to your esophagus)
• Abdominal pain and cramping
• Feeling full quickly or lack of appetite

Symptoms tend to be more severe for me after eating. I often feel like my abdomen is about to explode—especially if I’ve had something that triggers gas production.

Hydrogen-Dominant SIBO

• Diarrhea (more common with hydrogen SIBO as it speeds up motility)
• Bloating and distention
• Abdominal pain and discomfort (but usually without the extreme constipation seen in methane SIBO)
• Nutrient malabsorption (leading to fatigue, brain fog, or even weight loss)

While I deal primarily with methane-dominant symptoms, the frustration and discomfort are very real regardless of which type you’re facing.

Hydrogen Sulfide SIBO (Less Common)

• Rotten egg-smelling gas
• Diarrhea or mixed bowel patterns
• Fatigue, joint pain, and brain fog

My Symptoms & Story (So Far)

My symptoms began in early November 2024, when what I thought was a simple stomach bug turned into something far more sinister. I became weak to the point where even walking around the block felt like a marathon. My abdomen would swell up whether I ate or not, and the pain and discomfort were unreal.

Some days, I could barely get off the couch without feeling like my insides were being strangled. I lost muscle mass and struggled to find anything I could eat that wouldn’t leave me feeling bloated or in pain. My symptoms were mainly methane-dominant, meaning I experienced severe constipation, bloating, belching, and a frustrating lack of appetite.

What made it even more difficult was not knowing what was causing these symptoms. By the time I was diagnosed, I had spent a small fortune on testing, supplements, and treatments that either didn’t work or made things worse. And as anyone with a chronic illness knows, it’s not just your health that takes a hit—it’s your finances, too.

The Financial Toll of SIBO

SIBO doesn’t just drain your energy; it can drain your bank account. From testing to supplements to doctor visits, the costs add up fast. I know this struggle well because I’ve lived it.

That’s why I’ve been open to finding other ways to bring in some extra income while I continue to heal. One option that’s worked for me is participating in sweepstakes programs where you can earn money by mailing envelopes. It's a simple, straightforward way to bring in some additional income. I’ll share more about that process in another post, but if you’re curious now, you can check out the details here.

SIBO is complex, frustrating, and often feels never-ending. But understanding your symptoms and what might be causing them is a huge step toward healing. Whether your symptoms are related to methane, hydrogen, or hydrogen sulfide, the key is finding the right treatment plan for you.

I’m still in the thick of this journey, but I’m finally starting to see some improvement. It’s not a straight line to healing, and it’s definitely not cheap. But I’m learning to embrace the process, tweak what isn’t working, and keep moving forward.

Have you experienced any of these symptoms? Drop a comment below and share your journey. You’re not alone, and I’d love to hear from you. 💪💚

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I am not a medical professional, and the information provided on this blog is for educational and informational purposes only. Always consult with a qualified healthcare provider before making any changes to your skincare or wellness routine.