Non-specific abdominal discomfort is a very common complaint among my patients, as well as many people across the country. These complaints often result from various causes that contribute to a perplexing disorder known as irritable bowel syndrome (IBS). The causes can be as individual as the person, but there is hope…
What is IBS?
Irritable bowel syndrome is a disorder consisting of abdominal discomfort or pain and other symptoms such as bad breath, belching, bloating/distention, gas, diarrhea or constipation. It is estimated that 13 million adults suffer from Irritable Bowel Syndrome with Constipation (IBS-C), [1] and less who have IBS with diarrhea. The latest term for IBS is “Functional Gastrointestinal Disorders” because symptoms can vary widely and they are not to the detectable tissue disease state as the inflammatory bowel diseases, Ulcerative Colitis (which I had for years) or Crohn’s Disease.
It is a frustrating disorder for both patient and doctor. For the doctor, there are no tests to prove the diagnosis as there is no detectable disease with imaging studies and endoscopy. Therefore, other intestinal conditions need to be excluded.
For the patient, medical treatments are only marginally effective. For example, the first of its kind prescription medication approved by the FDA in 2012 for IBS with constipation (IBS-C), Linzess®, only works in approximately 20% of people. [2] A newer one approved by the FDA this year for IBS with diarrhea (IBS-D), Eluxadoline (Viberzi®), works in just 13% of people. These drugs do not alter the natural history of the disease. In other words, they just mask the symptoms.
Therefore, it takes more than taking a pill to effectively treat these functional gastrointestinal disorders. It takes an understanding of the underlying causes of IBS which I’d like to explain here.
What causes IBS?
IBS has a few important contributing causes. The most predominate finding is gut “dysbiosis,” or an overgrowth of the unhealthy gut bacteria which produce methane and hydrogen gases. These bacteria and the gas they produce are thought to irritate the inside lining of the small and large intestine. When it irritates the nerves that control smooth muscle stimulation in the gut, called “peristalsis,” you can imagine that cramping, pains, and diarrhea or constipation result.
Yet there are other contributing factors besides just microbial dysbiosis that are important to know about. Traditionally IBS has been thought to be largely a brain-gut disorder, with many patients suffering gut symptoms along with psychological distress. Science now reveals there are other conditions inherent in IBS. We know that with most all patients suffering from IBS there are one or more of the following mechanisms [3] involved. I’ll address these in more detail in a follow up article, but let me just mention them here:
- Decreased intestinal barrier function (i.e. “leaky gut”) and the resultant immune dysregulation that triggers allergies and inflammation of chronic disease
- Intestinal lining hypersensitivity from neurotransmitters such as serotonin and dopamine that were formerly thought to be just in the brain, but now we know are more predominate in the gut
- Bile acid malabsorption
Therefore, the most successful treatments will be to improve the intestinal organisms through diet, prebiotics and antibiotics. Then look at brain-to-gut and gut-to-brain neurotransmitters. [4]
In my next article I will discuss how diet affects IBS, the best ways to improve intestinal organisms and gut-to-brain neurotransmitters. You’ll be interested to also learn about how Small Bowel Intestinal Overgrowth (SIBO) contributes to not only IBS, but several other illnesses that I just recently learned about.
To feeling good for optimal health,
Michael Cutler, M.D.
Easy Health Options
[1] Brandt LJ, Prather CM, Quigley EM, et al. Systemic review on the management of chronic constipation in North America. Am J Gastroenterol. 2005;100(suppl 1):S5-S21.
[2]Sood R, Ford AC. Linaclotide: new mechanisms and new promise for treatment in constipation and irritable bowel syndrome. Therapeutic Advances in Chronic Disease. 2013;4(6):268-276. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3807764/
[3] ornby PJ. Drug discovery approaches to irritable bowel syndrome. Expert Opin Drug Discov. 2015;10(8):809-24.
[4]Talley NJ, Holtmann G, Walker MM.Therapeutic strategies for functional dyspepsia and irritable bowel syndrome based on pathophysiology. J Gastroenterol. 2015 Jun;50(6):601-13. Epub 2015 Apr 29.
