The main function of the Large Intestine (‘Da Chang’ ~ ‘Great Intestine’) is to receive the remains of food sent down from the small intestine, absorb the good fluid from it and send the solid waste to be excreted. On another level, this also applies to our emotional wellbeing and those holding onto old feelings or going through intense periods of emotional upheaval such as grief will find that their bowel movements will become irregular of difficult.
Paired with the Lung, both are related to the element of Metal and the season of Autumn with the Large Intestine most active between 5-7am. The Large Intestine is charged with allowing us to move on, to facilitate free and fluid movement – on both an emotional and physical level. The natural movement of Large Intestine Qi is downwards, like that of the Lung Qi. When both move down, there is a natural transformation and movement of substances in the body and thus our energy and digestive systems have a good chance of functioning well.
When the Qi of the large intestine becomes impaired we suffer constipation. The Large Intestine is also prone to issues of heat retention (Yang Ming or Yang Brightness) and to reduce fever, herbs or acupoints can be used to promote bowel movement (thus helping to reduce fever).
When we find ourselves holding onto past thoughts and feelings, particularly in a harmful manner, we should look towards the large intestine as a means of treating these. Not only does grief, worry and anxiety affect us mentally, but they consume a lot of blood and Qi, can raise the temperature of the body (Large Intestine heat) and cause digestive problems. Emotional well being is closely linked with physical and spiritual well being in Traditional Chinese Medicine and there really is no way to separate the emotional from the physical when a treatment is being considered. Promoting a healthy large intestine is therefore one way of helping to deal with emotional problems and it is worth considering whether physical problems in the digestive system are a symptom of unresolved emotional problems in a patient.
The Neijing describes the Large Intestine as Showing the Way or Showing the Dao. The Dao is the ‘way of life’ or the great ineffable energy or oneness. It is interesting that such an organ tasked with preparing waste should be described in such a manner but the Large Intestine’s role in getting rid of the used and unwanted in our lives should not be underestimated. It is only by transforming that which we no longer require do we get to move on in life. We have to leave things go, we have to get rid of energy that is of no use to us anymore. By doing so, we can continue on our own Dao.