It is essential that we understand the digestive fire or ‘Agni’ in Ayurveda. After the doshas, you’ll hear Agni referred to most often in the Ayurvedic Texts.
Many ayurvedic doctors say that the treatment of diseases of the body is in fact the treatment of Agni. This Agni is responsible for transforming food into substrates/ metabolites that can be used by the body to balance and nourish the tissue systems.
Even if we have arranged for all kinds of suitable foods in the right combination, our body cannot utilize them without the help of Agni –The Digestive Fire.
In the body, the Agni or fire is manifested as Pitta Dosha, but still contains aspects of each element. The Pitta Dosha is predominantly Fire & Water. The qualities of Pitta as sharp, and light are due to the fire element. Lightness is also contributed by the space element. Air gives the property of mobility and lightness. The properties of mild unctuousness, the capacity to spread evenly, and the fluid state are due to the water element. The earth element gives a peculiar odor to Pitta, the representative of Agni in the body. Knowing that Agni in the body contains the five elements becomes more relevant when we talk about the Four States of Agni:
The normal state (Sum Agni) – This stage is a balanced state of all the five elements by their representative Doshas in the body. The person having a ‘Sum Agni' is able to digest reasonable quantities of food without any adverse signs and symptoms. The person enjoys perfect health with the season, food, or habits affecting the Agni. The person is bestowed with strength, radiance, immunity to diseases, an abundant life force, and long life.
The irregular state of Agni (Visham Agni) – When Vata dosha (Air & Space) becomes aggravated in the body under the influence of various causative factors, it also aggravates the elements of Air and Space present in the Agni, so it shows irregular behavior, a distinct characteristic of the Air element. It is sometimes able to digest the food and sometimes not. There is sometimes diarrhea and at times constipation, flatulence, colicky pains, low backache, and various Vata disorders.
Hyper state of Agni (Tikshna Agni) – When Pitta Dosha gets aggravated due to causative factors, then it increases the fire element in the Pitta residing in the Abdomen area as the digestive fire or Agni. This results in an intense state of digestion and metabolism. This state causes the person to eat large quantities of food. Once the food is digested, the increased fire element in the digestive fire causes a dry palate, parched mouth, a burning sensation, acidity, and heat burn. It may also cause gastritis, dysentery, or colitis.
Hypo state of agni (Manda Agni; manda in Sanskrit means slow) – When Kapha aggravates Agni it also aggravates the elements of Water and Earth in the digestive fire. As Water and Earth elements antagonize the properties of Fire, the digestive Fire becomes doused. It is not able to digest even small quantities of food, leading to a slow metabolism. There is a fullness of the stomach, nausea, loss of appetite, and systemic Kapha disorders like colds and cough, lethargy, and cold clammy skin.
So we can see that in All these Stages of Agni, there is an effect on the gastrointestinal tract due to the derangement of one or more of the elements in the Digestive fire – the Agni.