Large Intestine
The Large Intestine (大肠, Dà Cháng) is a Fu (Yang) organ belonging to the Metal element, paired with the Lung. Its main functions are receiving waste from the Small Intestine, reabsorbing fluids, forming feces, and eliminating waste through the anus. It is known as the "Official of Transmission and Transformation."
Five Element Correspondences
Season
Autumn
Climate
Dryness
Emotion
Grief, sadness (shared with Lung)
Color
White
Taste
Pungent/Acrid
Sound
Crying, weeping (shared with Lung)
Direction
West
Sense Organ
Nose (shared with Lung)
Body Tissue
Skin and body hair (shared with Lung)
Body Fluid
Jin (thin fluids) - participates in reabsorption
Peak Hours
05-07
Meridian
Large Intestine Meridian
Educational content · Consult qualified TCM practitioners for diagnosis and treatment
Overview
The Large Intestine (大肠, Dà Cháng) is one of the six Fu (Yang) organs in Traditional Chinese Medicine. Unlike in Western medicine where the large intestine is primarily viewed as an anatomical structure, in TCM it represents a functional system focused on waste elimination and fluid reabsorption. The Large Intestine receives food residues from the Small Intestine, absorbs remaining fluids, and transforms the waste into feces for elimination through the anus.
As a Fu organ, the Large Intestine follows the principle of "transmitting and transforming without storing" (泻而不藏), meaning it must keep substances moving through rather than holding onto them. This is captured in the TCM maxim "the six Fu organs function best when unobstructed" (六腑以通为用). The Large Intestine is paired with the Lung in an interior-exterior relationship, both belonging to the Metal element and sharing qi communication through their connected meridians.
The Large Intestine's health directly reflects the overall state of digestive function and fluid metabolism. When functioning properly, bowel movements are regular and well-formed. Dysfunction leads to either constipation (when too dry or qi stagnates) or diarrhea (when dampness accumulates or cold invades), making the Large Intestine central to many digestive complaints treated in clinical practice.
Historical Context
The Large Intestine has been recognized as a distinct organ system since the earliest TCM texts. The Huangdi Neijing (Yellow Emperor's Classic, circa 200 BCE) established its fundamental functions, calling it the "Official of Transmission and Transformation." The Lingshu section provided detailed anatomical descriptions, noting its connection to the Small Intestine at the ileocecal valve (阑门, lán mén) and its passage to the anus (魄门, pò mén).
Li Dongyuan's Pi Wei Lun (Treatise on the Spleen and Stomach, 13th century) elaborated on the Large Intestine's role in fluid metabolism, establishing the concept of "Large Intestine governs jin" and explaining how the intestines work with the Stomach to distribute fluids throughout the body. The interior-exterior pairing with the Lung became clinically significant, with later physicians recognizing how Lung disorders could affect bowel function and vice versa.
Physiological Functions
Transmitting and Transforming Waste
传导糟粕 (Chuán Dǎo Zāo Pò)The Large Intestine's primary function is receiving food residues from the Small Intestine, forming them into feces, and eliminating them through the anus. This is the final stage of digestion, earning it the classical title "Official of Transmission and Transformation" (传导之官). This function depends on proper qi movement and coordination with the Stomach's descending, Spleen's transporting, Lung's descending, and Kidney's consolidating functions.
Governing Fluids (Jin)
主津 (Zhǔ Jīn)The Large Intestine reabsorbs a portion of fluids from food residues as they pass through, returning moisture to the body while forming solid stool. This function is called "governing jin" (thin fluids) and plays an important role in fluid metabolism. Dysfunction leads to either diarrhea (insufficient absorption) or constipation (excessive absorption or fluid deficiency).
Descending and Unobstructing
通降 (Tōng Jiàng)As a Fu organ, the Large Intestine must maintain downward, unobstructed movement of its contents. The principle "Fu organs should be unobstructed" (腑以通为用) is especially relevant here. Stagnation leads to constipation, abdominal distension, and pain. The Lung's descending qi supports this function through their interior-exterior relationship.
Relationships with Other Organs
Other
The Lung and Large Intestine share an interior-exterior (表里) relationship through their meridian connections. The Lung's descending function supports the Large Intestine's ability to transmit and eliminate waste. When Lung qi fails to descend properly (such as from worry or grief), it can cause constipation. Conversely, Large Intestine Heat or blockage can impair Lung qi, causing chest oppression and difficulty breathing. Clinically, treating the Lung often benefits the Large Intestine and vice versa.
Other
The Spleen's transformation and transportation function provides the qi necessary for proper Large Intestine function. Spleen Qi Deficiency often leads to Dampness accumulation in the Large Intestine, causing loose stools or diarrhea. The Spleen also helps maintain the Large Intestine's ability to reabsorb fluids properly.
Other
The Kidney provides Yang qi that warms the Large Intestine and supports its function. Kidney Yang Deficiency can lead to early morning diarrhea ("cock-crow diarrhea"). The Kidney also controls the "two lower orifices" including the anus, so Kidney Qi Deficiency may cause prolapse or incontinence.
Other
The Small Intestine passes food residues and remaining fluids down to the Large Intestine after separating the pure from the impure. If the Small Intestine fails in its separating function, it directly affects Large Intestine function, often causing diarrhea or abnormal stools.
Controlling
The Liver's free-flowing qi movement affects Large Intestine function. Liver Qi Stagnation can "attack" the Large Intestine, causing alternating constipation and diarrhea, abdominal pain, and bloating—patterns commonly seen in irritable bowel syndrome. Liver Fire can also transmit to the Large Intestine, causing urgent, explosive bowel movements.
Other
Both organs belong to the Yang Ming channel system and share a descending nature. The Stomach's descending function initiates the downward movement that the Large Intestine completes. Stomach Heat often accompanies Large Intestine Heat in acute conditions.
Common Pathological Patterns
Key Manifestations
Key Manifestations
Key Manifestations
Key Manifestations
Key Manifestations
Tongue Manifestations
Large Intestine patterns show characteristic tongue changes. Damp-Heat patterns present with a red tongue body and yellow greasy coating, often more pronounced toward the root (which corresponds to the lower jiao). Heat/Dryness patterns show a red, dry tongue with yellow coating that may be thick and dry, or the coating may be absent. Cold patterns display a pale, moist tongue with white coating. Qi Stagnation may show a slightly purplish tongue or normal appearance with distended sublingual veins.
Pulse Manifestations
Large Intestine patterns manifest in specific pulse qualities. Damp-Heat produces a Slippery, Rapid pulse reflecting the pathogenic accumulation. Heat patterns show a Rapid, Full, possibly Flooding pulse. Cold patterns present with a Deep, Slow, Weak pulse. Dryness/Fluid Deficiency creates a Thin or Choppy pulse due to insufficient fluids. Qi Stagnation typically shows a Wiry pulse. The pulse position associated with the Large Intestine is typically the right cun (inch) position at the superficial level, shared with the Lung.
Clinical Relevance
The Large Intestine is central to treating digestive complaints including constipation, diarrhea, irritable bowel syndrome, inflammatory bowel disease, and hemorrhoids. Pattern differentiation is essential: constipation may arise from Heat (requiring cooling and moistening), Qi Stagnation (requiring movement), or Deficiency (requiring tonification), each requiring different treatment approaches.
The Lung-Large Intestine relationship has important clinical applications. Treating the Lung can benefit chronic constipation, while addressing Large Intestine Heat can help resolve certain skin conditions and respiratory issues. The principle "when treating the intestines, consider the Lung" guides many clinical decisions.
Dietary and lifestyle factors strongly influence Large Intestine health. Excessive cold, raw foods can cause Cold patterns; greasy, spicy foods promote Damp-Heat; emotional stress (especially worry) impairs qi flow. Patient education about these factors is an essential part of treatment.
Classical Sources
Huangdi Neijing Suwen
Chapter 8: Ling Lan Mi Dian Lun (Treatise on the Secret Classics of the Spiritual Orchid)大肠者，传道之官，变化出焉
The Large Intestine is the official of transmission and transformation; change and transformation emerge from it
Huangdi Neijing Lingshu
Chapter 10: Jing Mai (Meridians)大肠主津
The Large Intestine governs the jin (thin fluids)
Pi Wei Lun (Treatise on the Spleen and Stomach)
Chapter on Large and Small Intestine大肠主津，小肠主液，大肠、小肠受胃之荣气，乃能行津液于上焦
The Large Intestine governs jin, the Small Intestine governs ye; both intestines receive the nourishing qi from the Stomach, thus enabling the movement of fluids to the upper burner
Huangdi Neijing Lingshu
Chapter 31: Chang Wei (Intestines and Stomach)回肠当脐，在环回周叶积当下，回运环反十六曲
The coiled intestine is at the level of the navel, winding and folding below, turning and coiling in sixteen curves
Modern References
The Foundations of Chinese Medicine: A Comprehensive Text for Acupuncturists and Herbalists
Comprehensive coverage of Large Intestine physiology and pathology from a TCM perspective
Diagnosis in Chinese Medicine: A Comprehensive Guide
Detailed pattern differentiation for Large Intestine disorders
Chinese Acupuncture and Moxibustion
Standard reference for Large Intestine meridian and related acupoints