Understanding Different Types of Sibo

Woman holding stomach in pain

What is SIBO?

Small Intestinal Bacterial Overgrowth (SIBO) describes an overgrowth of certain bacteria in the small intestines. While it is normal for the small intestines to have bacteria, it becomes a problem when the bacteria stays in the small intestine for too long or in too high of a quantity. There are 3 types of sibo: hydrogen, methane, and hydrogen sulfide sibo.

Symptoms associated with the 3 types of sibo

Some of the primary digestive symptoms that occur as a result of SIBO include: 

  • Bloating
  • Stomach distention
  • Gas
  • Constipation
  • Loose stool
  • Nausea
  • Early satiety (feeling full quickly) 

Other symptoms include:

  • Fatigue/low energy
  • Brain fog
  • Headaches
  • Joint Pain
  • Loss of appetite/ weight loss
  • Nutrient deficiencies from malabsorption
  • Depression and anxiety 

It can take some people a long time to receive an accurate SIBO diagnosis since symptoms occur inside and outside of the gut. Many SIBO symptoms overlap with other conditions as well. There are similarities between the types of sibo as well.

Also, we are still learning how the different types of SIBO develop. Some scientists believe SIBO occurs when movement in the small intestine slows down. When the movement of food and waste slows down, the bacteria in the large intestine have a better chance of moving up into the small intestines. This creates a breeding ground for bacteria.

Risk factors for the different types of sibo

SIBO can be caused by:

  • Complications from surgery
  • A structural problem in the small intestine
  • An injury to the small intestine
  • Using PPIs (proton pump inhibitors)
  • Opioid use
  • GI conditions like IBS/IBD
  • Medical conditions like Crohn’s, Celiac disease, and Diabetes 

3 types of sibo

Hydrogen Dominant SIBO

Hydrogen-dominant SIBO occurs when too many bacteria grow in the small intestines. A common symptom of hydrogen-dominant SIBO is diarrhea. 

Methane Dominant SIBO

Other bacteria in our small intestine make methane gas. When there’s too much methane, it can slow down how quickly you digest food. This type of sibo can lead to constipation and make it harder for food to move through your intestines.

Hydrogen Sulfide SIBO

This type of SIBO happens when different bacteria create hydrogen sulfide gas. This gas causes symptoms of diarrhea as well.  

Testing for the Different Types of Sibo


The gold standard test for SIBO is done by taking a sample of fluid from the small intestine. While the sample from the small intestine may be more accurate, the sample is hard to extract. Additionally, there are limitations to the test. 

First, the test only takes a sample from one part of the intestine. Second, it’s difficult to tell the difference between the healthy and harmful bacteria in the sample. 

SIBO Breath Test

The most common test used for SIBO is a breath test. The bacteria in your gut ferment carbohydrates and produce gases. The gases are exhaled through the lungs. SIBO breath tests are used to diagnose SIBO by measuring the byproducts. Breath tests are less invasive than the gold standard test but they may not be as accurate. 

Stool Testing

Stool testing cannot diagnose SIBO but they may be able to provide some insight into what is causing or contributing to the overgrowth of bacteria in the small intestine. 

Treatment for the different types of sibo


Antibiotics, such as Rifaximin, are considered a standard treatment for SIBO in conventional medicine. More than one course of antibiotics may be needed to treat SIBO. A course of antibiotics is usually two weeks. A single course is not always effective at eliminating SIBO. 

Herbs and Supplements

Antimicrobial herbs may also be recommended to help eradicate SIBO. Work with a doctor who specializes in functional medicine if you’re interested in exploring alternative approaches to treating SIBO. Herbs and supplements are sometimes used in combination with antibiotics. 

Talking to a doctor is essential if you suspect you have one of the 3 types of SIBO. Doctors can you decide the help right treatment because what works for one person might not work for another.


Your diet can play a key role in reducing the chances that SIBO reoccurs. 

Eat and drink foods that promote regular, daily bowel movements to reduce recurrence. Drinking enough water and consistent intake of soluble fiber foods can support daily movement. Check out this article for a list of high-fiber foods for constipation.

Additionally, meal spacing is a strategy that can prevent SIBO or SIBO reoccurrence. Leave at least 4 hours between meals to prevent opportunistic bacteria from moving from the large intestine to the small intestine. 

If prescribed antibiotics, following a low FODMAP diet might reduce symptoms like gas, bloating, and changes to stool. Low FODMAP diets are not recommended long term because they can damage the microbiome.

Work with a Registered Dietitian who specializes in digestive health and understands how to implement a low FODMAP diet if you suspect an intolerance to FODMAPs. This will streamline the process and avoid the frustrations of navigating a complicated elimination diet alone. 

5 Post SIBO Treatment Tips

To treat, you first need to determine which of the 3 types of sibo you have. Then, treatment will depend on your result and the specific symptoms you have as well. What you do after treatment will determine whether you fall into the 65% of people who have recurring SIBO. 

Follow these tips to reduce your chance of recurrence:

1. Move throughout the day

Regular movement throughout your day helps keep things moving through your intestines. Small bouts of movement throughout the day are more effective than a one-hour workout and then spending the rest of the day sitting at your desk.

2. Stop eating 3 hours before bedtime

When you’re not eating, your gut’s “house cleaning” mechanism can sweep through and clear out leftover food debris. It can only do its job in the fasted state.

3. Focus on a plant-forward plate

More plants on your plate means crowding out processed foods that fuel inflammatory bacteria. Processed foods can slow down motility and lead to constipation and bacterial overgrowth. 

4. Practice stress management

Stress can inhibit the gut-brain connection, reduce stomach acid, and lead to GI symptoms. 

5. Follow food safety guidelines

Food poisoning is a trigger for SIBO recurrence. Avoid cross-contamination and cook food to the recommended internal temperatures. 


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