The Small Intestine's main function is to receive partially decomposed food and drink from the Stomach, digest, and absorb them further. Then it separates the pure part from the impure part. The pure part is useful and is sent to the Spleen to create Grain Qi. The impure part is sent to the Large Intestine. Its separating Fluids function is assisted by Kidney Yang, which provides the Qi and Heat to make this process happening. The Small Intestine has a direct impact on the Bladder and it influences the urinary function. In the case of a urinary problem, the Small Intestine should be examed.
From a psychological perspective, the Small Intestine receives things, separates irrelevant ones from these are useful. It is said to have some connection with the Heart and Mind and thus influences mental clarity and judgment. It assists in decision making. Gall Bladder also plays a role in decision making but it is more on giving the initiative and courage to make decisions. While the Small Intestine is to discriminate and differentiate what is relevant and what isn't.
After receiving partially decomposed food from the Stomach, the Small Intestine digests and absorbs them further and then divide the pure part from the impure part. The pure part is useful and is sent to the Spleen. It then gets transformed into Grain Qi to nourish other Organs. The Large Intestine receives the impure part and then separated them further into waters and solid stools. The clear waters are transported to the Urinary Bladder to be excreted from the body.
The Small Intestine separates Fluids after receiving them from the Stomach. Body Fluids are divided into a clear part, traveling to the Bladder for excretion as urine, and a turbid part, traveling to the Large Intestine to be absorbed further. Therefore, the Small Intestine has a direct impact on the Bladder and it influences the urinary function. In the case of a urinary problem, the Small Intestine should be examed.
By providing Qi and Heat, Kidney Yang rules the separating function of Small Intestine. If this function doesn't work properly, excessive or scanty urination can appear, depending on whether the small Intestine is Cold or Hot.