Why Methane SIBO (IMO) causes constipation

Constipation can be an annoying, frustrating, and painful part of digestive issues, especially if you have methane Small Intestine Bacterial Overgrowth (SIBO). However, why does methane SIBO cause such bad constipation, while hydrogen SIBO and hydrogen sulfide SIBO often result in diarrhea?

As a SIBO patient advocate, I often hear that question from methane SIBO patients. If you can relate, you’re in the right place!

The Methane SIBO-Constipation Connection

Small Intestinal Bacterial Overgrowth, or SIBO, is a condition where an overgrowth of bacteria occurs in the small intestine. What sets methane-dominant SIBO apart is the specific type of gas produced by the overgrown bacteria. Methane gas, primarily produced by Methanobrevibacter smithii, plays a significant role in influencing gut motility (the ability of your gut to “sweep” food through the digestive tract) and subsequently contributing to constipation.

Transit Time

Methane gas has the unique ability to slow down the movement of the digestive tract, a process known as gut motility. This sluggish movement can result in food remaining in the intestines for an extended period, leading to constipation. 

The Migrating Motor Complex (MMC)

The Migrating Motor Complex (MMC) is a contraction pattern that sweeps through the intestines during periods of fasting. Its primary role is to clear food particles from the gut. Methane SIBO interferes with the MMC’s effectiveness and can contribute to constipation by stopping the “push” needed to cause a bowel movement. 

Neuromuscular Alterations

Methane gas also affects the gut-brain connection, and if you’re familiar with our work at SIBO SOS®, you’ll know this is a big deal. The gut-brain connection includes the intricate network of nerves that control gut motility. Research suggests that Methanobrevibacter smithii (the methane) might influence the release of neurotransmitters that regulate the movement of the intestines. With methane-dominant SIBO, these altered neurotransmitter levels can lead to weakened contractions, which are essential for propelling stool through the intestines.

Water Absorption

The slow transit time caused by methane SIBO can result in excessive water absorption from your stool, making it dry and hard. Hardened stool is difficult to pass, which contributes to constipation and pain during bowel movements.

Normal proper gut motility helps maintain a balance between water absorption and fluid retention, preventing stool from becoming excessively dry.

Managing Methane SIBO-Related Constipation

Understanding the connection between methane SIBO and constipation is a significant step toward learning the tools to manage it effectively! 

Here are strategies that can help symptoms while you’re healing from methane SIBO:

  1. Treat the methane. It may sound obvious, but make sure you’re working with a practitioner to eradicate the bacterial overgrowth in your small intestine, whether it be through SIBO-specific antibiotics, herbal microbials, the Elemental Diet, or something else. Rifaximin is often used successfully for methane SIBO. If you’re looking for more information about how to successfully treat methane SIBO, check out the SIBO Recovery Roadmap® Course.
  2. Use prokinetics. Prokinetics can enhance gut motility, assisting in the movement of stool through the intestines. These medications help counteract the sluggishness caused by methane gas and restore more regular bowel movements.
  3. Include fiber in your diet. While you shouldn’t add too much fruit to your diet while treating SIBO due to the sugar content, try to find ways to add fiber to your diet. Guava is a good example of a low-sugar, high-fiber fruit that can help cause bowel movements. 
  4. Exercise. Another exercise benefit: it can help the Migrating Motor Complex do its job! 

While constipation is an frustrating symptom, remember that there is hope in treating methane SIBO. With the right practitioner and tools, you can be well. 
If you’re looking for more information about treating SIBO, check out our other blogs here, our SIBO Recovery Roadmap® Course here, and our masterclasses and summits here.

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