Allen M. Schoen, MS, DVM, PhD (hon.)
Acupuncture (AP) has been used successfully in the treatment of numerous gastrointestinal (GI) conditions including vomiting and diarrhea, constipation and pancreatitis. The effects of acupuncture on gastrointestinal conditions may be described both from a conventional Western medical perspective as well as from a traditional Chinese medical (TCM) perspective. The Western medical perspective will be the primary focus of this presentation with additional TCM perspectives presented. Communication pathways mediating the AP response are relatively complex. Numerous studies have documented the efficacy of acupuncture in the treatment of GI conditions. Studies have focused on somatovisceral effects, regulation of blood flow, GI motility and secretions. Specific AP points have been found to have reproducible effects on the GI tract. The NIH '97 Consensus on AP for human gastrointestinal conditions found that acupuncture was effective for peptic ulcers, diarrhea, ulcerative colitis and irritable bowel disease. Acupuncture has been found to regulate gastric secretions, gastric motility, hormone and neuropeptide release and metabolism.1
One of the most significant theories of Chinese medicine corresponds to the Western medical concept of somatovisceral reflexes where the location of acupuncture points, related neurovascular nodes, underlying skin zones and muscles distributions are related to specific internal organs.2 These relationships may be utilized both diagnostically and therapeutically. Viscerosomatic relationships are recognized as sensitivity and reactivity in acupuncture points, spinal segments and related dorsal thoracic and lumbar musculature corresponding to organ-referred pain in specific organs. Somatovisceral reflex response to stimulating cutaneous and muscle sensory afferents has been measured in several different internal organs affecting both sympathetic and parasympathetic activity.2 Somatovisceral neurons are reported to be located in laminae I and V of the dorsal horn and in the ventral horn of the spinal cord.3 Convergence of somatic and visceral afferent neurons provides the main anatomical basis for AP point (nodal) stimulation to influence internal organs.2 Animal studies have documented that AP is effective in normalizing both hypomotility and hypermotility. Comprehensive reviews of the neurophysiologic basis of AP for GI conditions are available.2,5
Studies on GI motility have focused on two key AP points, PC-6 (Neiguan and ST-6 (Zusanli). Research on PC-6 includes 33 controlled trials published worldwide as of 1996 for use of PC-6 for nausea & vomiting with 27/29 trials showing statistically significant positive results. Stimulation of Pericardium 6 (PC6) produced significant reduction of perioperative emetic sequelae. Electroacupuncture reduced morphine-induced emesis in ferrets with 5 minutes of stimulation of PC6 @ 1.0 Hz & 5.0 Hz (n = 5/group).5 From a TCM perspective, PC-6 (Nei-Guan) is considered the gate to the heart and lungs, calms the heart and regulates Qi. It can be used to treat vomiting, gastritis, megaesophagus, behavioral problems, anxiety and epilepsy. ST-36 (Zusanli) has been found to have analgesic and spasmolytic effects on the GI tract, regulates gastric acidity and has a homeostatic effect in endocrine and metabolic disorders. Clinically it has been used to treat gastroenteritis, pancreatitis, impactions, and ileus. It has been found to increase plasma gastrin in rabbits and dogs. It is mediated by b-endorphins and somatostatin.5 From a TCM perspective it is considered a master point and tonification point for any deficiency.
It has been used for feline obstipation syndrome to increase GI motility and secretions. From a TCM perspective this is considered an interior cold condition in the intestines due to a Qi deficiency or a Blood or Yin deficiency.
Acupuncture is beneficial for the treatment GI hypermotility and diarrhea whether it is due to a viral/bacterial gastroenteritis such as parvovirus or due to inflammatory bowel disease, lymphocytic, plasmacytic colitis in cats or pancreatitis. Key AP points to consider in the treatment of diarrhea in all of these conditions include: LI-4, LI-11, ST-36, SP-6, BL-20, BL-21. Additional points may be chosen based on a TCM perspective. From a TCM perspective, diarrhea may be considered due to damp heat invading the spleen, retention of food, cold-damp invading the Spleen, or Spleen Qi deficiency or a Kidney/Spleen deficiency.
Acupuncture may also be beneficial for controlling vomiting associated with esophageal achalasia/ megaesophagus. Achalasia is the failure of the esophagogastric sphincter to relax at swallowing. Transcutaneous electrical stimulation (TENS) at LI-4 & SI-3/HT-7 sig. decreased lower esophageal sphincter pressure in humans w/ achalasia. It causes an increased plasma vasoactive intestinal peptide release. This is an inhibitory neuropeptide that may relax lower esophageal sphincters. In one study on 5 dogs with idiopathic megaesophagus, there was a 70% resolution of regurgitation and increased weight gain using points PC-6, PC-9, HT-9, ST-36, LI-4, LI-11 and ST-40 with dry needles 10minutes twice a week for 4 weeks.
From a TCM perspective, vomiting may be considered a shi excess with external pathogenic factors of cold or heat or liver invading the Stomach, or Stomach Fire, or Cold Phlegm from fluids in the stomach or due to a Stomach Yin deficiency.
Clinically, AP may be used as an adjunct to conventional medicine in the treatment of many companion animal GI conditions. In areas where conventional medications are not available, it can be quite beneficial on its own. AP has been found to be beneficial in small animal practice in the treatment of GI motility problems including vomiting, diarrhea and constipation. AP may also be used for GI pain and inflammation from pancreatitis, tenesmus, rectal prolapse and immunomodulation in infectious GI disease. A comprehensive table of empirical AP points commonly used to treat various conditions is available5. AP should be integrated into most traditional approaches GI conditions.
1. NIH Consensus Study on Acupuncture, Alt. Tx. 4:1:22. Jan '98.
2. Kendall D. Dao of Chinese Medicine. Oxford University Press, NY, 2002;256–285.
3. Cervero F. Dorsal horn neurons and their sensory inputs. In: Spinal Afferent Processing, T Yaksh, ed. Plenum Press, N.Y., 1986;197–216.
4. Lixing L, et al. Alt & Comp Med 1995;1(3):257–261.
5. Dill S, Bierman N. Acupuncture for gastrointestinal disorders. In: Schoen A, 2nd ed. Veterinary Acupuncture, Ancient Art to Modern Medicine. Mosby, St Louis, MO., 2001;239–260.