The causes for IBS are not completely understood in the scientific community, but multiple evidences revealed that one of the IBS could be stress-sensitive disorder. The Automatic Nerve System (ANS), along with the hypothalamic-pituitary-adrenal (HPA) axis, are the two main central response systems to stress. IBS is considered a disorder of altered brain-gut interactions, which can affect the ANS. In turn, this can cause disturbances in gastrointestinal function, resulting in symptoms such as abdominal pain and diarrhea and/or constipation. There is also increasing evidence that the gut microbiome is altered in IBS.
How does acupuncture work for IBS then?
As can be seen in the images below, 10th to 12th intercostal nerve branches surround the abdomen, and these automatic nerves controls the function of digestive organs. Ancient Chinese medicine practitioners through tests and errors mapped out groups of points along the automatic nerve system as well as other tissue systems in the abdominal region amongst the rest of the body regions.
By selecting and inserting acupuncture needles along the points next to the automatic nerves, ANS can be stimulated and thus acupuncture can bring the sympathetic nerve system and parasympathetic nerve system back to homeostasis. Through acupuncture therapies, 1) intestinal peristalsis would be functioning properly and normal to move feces and gas, which would reduce constipation and bloating; 2) gastric acid quantity would be reduced, and the PH level in the stomach would be normal; 3) the gastric membranes would be repaired and thus less pains in the stomach; 4) fluids would be better absorbed in the small intestines thus there would be less diarrheas, sticky stools, or loose stools.