Causes of IBS

• Introduction and Summary
• 1) Stress and IBS
  • CRH
  • Adrenaline
• 2) Inflammation
• 3) Oxidative Stress
• 4) Serotonin
• 5) Low cyclic AMP
• 6) Low cyclic GMP
• 7) Excess IDO, Low Tryptophan
• 8) Microbial Imbalance: Lack of Good Gut Bacteria, Excess Bad Bacteria
• 9) Intestinal Permeability
• 10) Bad Diet: Excess Sugar
• 11) FODMAPs
• 12) TGR5 and Bile
• 13) Undiscovered Infection
• 14) Antibiotic Usage
• 15) Low Stomach Acidity
• IBS and Hormones
• 16) Low T3
• 17) Excess CCK
• 18) Excess Cortisol
• 19) Sex Hormones: Testosterone, Estrogen, Progesterone
• 20) Decreased Motilin
• 21) Excess VIP
• 22) Low PYY
• 23) Ghrelin
• 24) Secretin, GIP
• 25) Low Oxyntomodulin
• 26) Somatostatin
• 27) Excess Substance P
• 28) TRH
• Other
• 29) Defective Mucus Layer
• 30) Guanylate cyclase 2C
• 31) Nutrient Deficiencies
• 32) Lack of Soluble Fiber
• 33) Fat Malabsorption
• Genetics
• Excluding Other Conditions
• IBS is Commonly Found With:
• Disclaimer

Introduction and Summary

Ask your doctor about the cause of IBS and they will likely give you a blank stare.

The 3-minute assembly line churns and since you aren’t about to die, it’s on to the next case.

The NIH estimates that as many as 20% of Americans may experience signs of IBS. (R)

As you will see, IBS is a complex disease and there are many variables in the web of causes.

There are two main types of IBS – one that involves Diarrhea (IBS-D) and one that involves Constipation (IBS-C).

• Contractions (flow) that is too fast cause diarrhea predominant (IBS-D)
• Contractions that are too slow cause constipation-predominant IBS(IBS-C).

Food goes from your stomach to your small intestine, where it’s broken down into carbohydrates, fats, and proteins. Only simple sugars (glucose, fructose, galactose and mannose) can be absorbed into your bloodstream.

The carbohydrates that aren’t broken down or absorbed pass to your large intestine, where bacteria ferment them. Fermentation produces gas, which is normal. This fermentation is supposed to occur only in your large intestine.

So food goes from stomach-> small intestine->large intestine.

The large intestine is loaded with bacteria, but the rest of your gastrointestinal tract has relatively few bacteria. You are not supposed to have large amounts of bacteria in your small intestine.

When a person has bacteria in the small intestine, unabsorbed carbohydrates are fermented there, producing significant amounts of gas.

This causes cramping and burning because the gas stretches the small intestine. The gas can also push the intestinal contents rapidly toward your large intestine to cause diarrhea.

Bacteria generally ferment in your small intestines because your gut ‘flow'(motility/peristalsis) is slowed down in this area.

When people have diarrhea, it usually means the flow is quickened in the large intestine.

Gut pain comes from the neurons in your gut being ‘hypersensitive’, and this has many causes as you will see.

When your intestines expand, this is sensed by the neurons in your gut.  If your neurons are hypersensitive, this distension will feel uncomfortable or hurt.  Others will just feel bloated, but not pain.

One major cause of gut flow changes is because we have too little serotonin. Why?  Because the gut immune system is imbalanced.

This post is mainly about IBS, but other gut problems are often from the same causes.

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