Rectal examination is one of the four diagnostic methods in Traditional Chinese Medicine (TCM), which includes observation, inquiry, auscultation, and palpation. Traditional TCM rectal examination consists of two parts: pulse diagnosis and palpation. The pulse diagnosis is performed at the Cun Kou (cun pulse), while palpation primarily focuses on the skin, limbs, chest, abdomen, and perianal area. There is no record in ancient or modern TCM literature regarding palpation within the rectal cavity. Through long-term clinical experience, the author has found that information obtained from rectal examination can provide a basis for TCM syndrome differentiation, and rectal examination can serve as a supplementary method in guiding clinical diagnosis and treatment.
To distinguish it from the Western medical practice of rectal examination, which solely checks for pathological changes, the author refers to the rectal examination used for guiding syndrome differentiation as “Rectal Examination”. This article will preliminarily explore the normal and pathological signs of rectal examination based on the author’s clinical experience and insights.
1. Normal Signs of Rectal Examination
During rectal examination, the normal temperature of the intestinal cavity in healthy individuals is moderate, the rectal wall is soft and smooth, neither dry nor wet, and the thickness of the intestinal wall is uniform; the finger moves freely within the intestinal cavity without any stickiness or pressure sensation; the intestinal cavity is unobstructed, with no narrowing, and there is no significant fecal residue within the cavity; during the examination, the patient may feel slight distension or urgency but can tolerate it. When withdrawing the finger, the glove should not have any mucus or blood, and there should be no noticeable foul odor.
There are individual differences in rectal examination signs, such as taller individuals having wider and longer intestinal cavities, while shorter individuals have narrower and shorter cavities; obese individuals may have narrower cavities, while thinner individuals may have wider cavities.
2. Pathological Signs of Rectal Examination
1. Heat Signs
Heat signs refer to the sensation of higher temperature within the rectal cavity than normal. This elevated temperature is often a sensation rather than an increase measured at the anal surface, or there may be a slight increase at the anal surface without a rise in body temperature. However, in some patients (e.g., those with fever), the rectal examination may show heat signs with a higher anal surface temperature than normal.
Heat signs indicate heat syndrome, which can be differentiated into excess heat and deficiency heat. Distinguishing between excess and deficiency heat requires combining the four diagnostic methods. Heat signs are commonly seen in conditions such as fever, perianal abscess, constipation, and rectal inflammation. Excessive heat is often associated with intense heat toxin or internal heat accumulation, while mild heat is related to yin deficiency internal heat and damp-heat.
2. Cool Signs
Cool signs refer to the sensation of lower temperature within the rectal cavity than normal. In most cases, this is a sensation felt by the examiner, and sometimes it can also be a decrease measured at the anal surface. Clinically, examples of decreased anal temperature can be seen when some patients report that suppositories inserted into the rectal cavity are expelled intact after a long time.
Cool signs indicate deficiency-cold syndrome and are commonly seen in patients with deficiency-cold constitution, such as yang deficiency constipation or deficiency-cold abdominal pain.
3. Dampness and Slippery Signs
Dampness and slippery signs refer to excessive moisture within the rectal cavity, with a slippery wall. These signs indicate dampness, deficiency, and cold, primarily seen in conditions of internal dampness, spleen deficiency with excessive dampness. Commonly associated with inflammatory bowel disease, anal gland inflammation, rectal submucosal abscess, diarrhea, etc., these signs are often related to the presence of significant mucus, pus, or exudate within the rectal cavity. The use of suppositories, oils, or enemas can also present as dampness and slippery signs, requiring careful differentiation.
4. Dry Signs
Dry signs refer to the rectal wall being dry with little moisture. These signs indicate heat, dryness, insufficient yin blood, and depletion of body fluids. They are commonly seen in conditions of internal heat accumulation, blood deficiency with dry intestines, dry-heat accumulation, insufficient yin blood, or insufficient body fluids. Often observed in cases of hard stools and inflammatory bowel disease.
Dry signs can coexist with heat signs and astringent signs, leading to dry-heat signs or dry-austere signs. Dry-heat signs indicate dryness and heat, commonly seen in heat accumulation constipation, while dry-austere signs indicate insufficient yin blood and body fluids, often seen in deficiency-related constipation.
5. Astringent Signs
Astringent signs refer to the rectal wall being sticky, with significant resistance when inserting or moving the finger, even giving a sensation of wrapping around the finger.
Astringent signs indicate dryness and dampness stagnation. Commonly seen in patients with heat accumulation constipation or spleen deficiency with damp-heat accumulation, possibly related to excessive dryness of the rectal wall or excessive stickiness of secretions within the cavity. Clinically, patients often present with hard stools that are difficult to pass or sticky stools that do not feel complete. Commonly seen in constipation and inflammatory bowel disease.
Astringent signs can coexist with dry signs and damp signs. Dry-austere signs indicate deficiency of yin blood and body fluids, while damp-austere signs indicate damp stagnation and spleen deficiency with damp-heat.
6. Hard Signs
Hard signs refer to the rectal wall being hard and lacking softness.
Hard signs are seen in conditions of damp-heat accumulation, stasis-heat, heat toxin accumulation, and phlegm-dampness accumulation. Commonly observed in inflammatory bowel disease, rectal inflammation, tumors, submucosal abscesses, schistosomiasis rectitis, radiation enteritis, and shortly after rectal surgery.
Hard signs often coexist with thick signs, forming hard-thick signs. Hard-thick signs indicate phlegm-dampness, blood stasis, dampness-heat, and tumors.
7. Thick Signs
Thick signs refer to partial or complete thickening of the rectal wall.
Thick signs indicate damp-heat, heat toxin, parasitic infections, and tumors. Commonly seen in conditions of dampness-stagnation, blood stasis, and heat toxin accumulation. Frequently observed in inflammatory rectal diseases, especially Crohn’s disease, schistosomiasis rectitis, submucosal fistulas, submucosal abscesses, and rectal tumors.
Thick signs often coexist with hard signs. In hard-thick signs, no obvious masses can be palpated, which is different from mass signs.
8. Mass Signs
Mass signs refer to palpable masses within the rectal wall.
Mass signs indicate phlegm, blood stasis, accumulation, and heat toxin. Observed in conditions of phlegm-blood stasis, phlegm-dampness accumulation, or heat toxin and damp-heat stagnation. Commonly seen in rectal polyps, anal-rectal cancer, rectal leiomyomas, and rectal stromal tumors, submucosal abscesses, and prostate enlargement. Soft masses are often phlegm-dampness or phlegm-dampness, while hard masses are often phlegm-blood stasis; soft, smooth, homogeneous masses with clear boundaries are often indicative of excess syndrome and benign lesions with a better prognosis; hard, uneven masses with unclear boundaries are often indicative of deficiency syndrome, mixed deficiency-excess syndrome, and malignant diseases with a poorer prognosis.
9. Wide Signs
Wide signs refer to an excessively wide and empty rectal cavity.
Wide signs often indicate normal conditions but can also indicate deficiency of yin blood and body fluids. In healthy individuals, this is often seen in tall or thin individuals. Clinically, it can also be seen in cases of deficiency of yin blood and body fluids, commonly observed in habitual constipation and blood deficiency constipation.
10. Narrow Signs
Narrow signs refer to a narrow rectal cavity, making it difficult to insert a finger.
Narrow signs indicate stasis, phlegm-dampness, tumors, and trauma. Commonly seen in conditions of stasis-heat, phlegm-dampness accumulation, or those caused by surgery or trauma. Frequently observed in rectal Crohn’s disease, rectal cancer, iatrogenic anal-rectal strictures, rectal tuberculosis, congenital rectal strictures, and constipation.
11. Relaxed Signs
Relaxed signs refer to a relaxed rectal wall with significant mobility. Although the rectal mucosa is relaxed, the patient does not feel any pressure on the finger, distinguishing it from pressure signs.
Relaxed signs indicate qi deficiency, yang deficiency, and insufficient qi and blood. Commonly seen in rectal prolapse, rectal mucosal prolapse, age-related anal-rectal relaxation, and anal incontinence due to qi deficiency, yang deficiency, and insufficient qi and blood.
12. Pressure Signs
Pressure signs refer to the finger inserted into the rectal cavity being significantly pressed by the surrounding tissues.
Pressure signs indicate deficiency and dampness. Commonly seen in conditions of insufficient qi, blood, yin, and yang, especially in cases of middle qi sinking. Also observed in spleen deficiency with damp-heat, damp-heat pressing down, spleen deficiency with excessive dampness, and qi deficiency with qi stagnation. Frequently seen in constipation (outlet obstruction constipation), inflammatory bowel disease, rectal prolapse, or rectal mucosal prolapse. Patients with pressure signs often experience difficulty and discomfort during bowel movements, along with a sensation of anal heaviness.
13. Prolapse Signs
Prolapse signs refer to the anterior wall of the rectum in females being relaxed, with significant mobility, and slightly pressing forward creates a pouch-like protrusion.
Prolapse signs indicate normal conditions but can also indicate deficiency. Prolapse signs are often seen in normal females, especially those who have given birth. In patients with constipation, they are often associated with qi deficiency, insufficient qi and blood, or kidney deficiency. Commonly observed in outlet obstruction constipation. Typically, rectal prolapse is clinically significant when a finger needs to be inserted into the vagina to apply pressure backward to assist in bowel movements.
14. Sensitivity Signs
Sensitivity signs refer to the patient feeling very sensitive and uncomfortable during the examination, making it difficult to tolerate. Especially when the finger touches the rectal cavity, the patient reacts more intensely, often resisting (such as involuntarily retreating backward).
Sensitivity signs indicate excess, wind, pain, and heat. Commonly seen in conditions of wind-heat pressing down, qi stagnation with blood stasis, and intense heat toxin. Frequently observed in inflammatory bowel disease, anal-rectal inflammation, anal gland inflammation, radiation enteritis, acute and chronic diarrhea, and diarrhea-type irritable bowel syndrome.
15. Dullness Signs
Dullness signs refer to the patient feeling dull during the examination, or patients with significant fecal accumulation in the rectal cavity feeling no urge to defecate.
Dullness signs indicate deficiency. Commonly seen in conditions of yang deficiency, dry intestines, blood deficiency, and qi deficiency. Frequently observed in cases of yang deficiency constipation, blood deficiency constipation, liver stagnation with spleen deficiency, and spleen deficiency with qi stagnation leading to rectal constipation, elderly constipation, and habitual constipation.
16. Pain Signs
Pain signs refer to the patient feeling anal pain and discomfort during the examination, even refusing to allow the finger to be inserted.
Pain signs indicate heat and stasis. Commonly seen in conditions of dry-heat accumulation, wind-heat pressing down, intense heat toxin, and qi-blood stasis. Frequently observed in anal fissures, perianal abscesses, anal-rectal inflammation, anal gland inflammation, radiation enteritis, thrombosed external hemorrhoids, and uterine fibroids.
Pain signs often coexist with sensitivity signs.
17. Residual Feces Signs
Residual feces signs refer to significant amounts of feces remaining in the rectal cavity, even completely obstructing the rectal cavity. Residual feces are mostly hard and dry, but can also be soft or loose.
Residual feces signs indicate deficiency, heat accumulation, and damp stagnation. Commonly seen in conditions of yang deficiency with internal accumulation, yin deficiency with dry intestines, blood deficiency with dry intestines, dry-heat accumulation, and spleen deficiency with damp stagnation. Frequently observed in various types of constipation. Typically, small amounts of hard fecal particles remaining indicate yin deficiency with dry intestines; large amounts of hard fecal masses remaining indicate heat accumulation or blood deficiency with dry intestines; soft or loose feces remaining indicate yang deficiency constipation; if there is residual loose feces, it often indicates spleen deficiency or qi deficiency; sticky loose feces indicate damp-heat signs or spleen deficiency with damp-heat.
The above are some of the author’s experiences and insights in using rectal examination to guide syndrome differentiation, which need further refinement.
The author has realized that rectal examination can effectively guide clinical syndrome differentiation, especially when symptoms are few or atypical, and the information from the four diagnostic methods is not typical; rectal examination often becomes a key basis for syndrome differentiation. The rectal examination method is simple and easy to perform, requiring no equipment, and has good potential for widespread use.Additionally, rectal examination should be combined with observation and auscultation when necessary. For example, when withdrawing the finger after rectal examination, if the glove has bright red blood, it often indicates wind-heat or damp-heat; if it has dark red or purple blood, it often indicates stasis or tumors. A foul odor from the glove often indicates damp-heat; a non-foul, fishy odor often indicates deficiency-cold.
Although rectal examination has been used clinically, the vast majority of doctors do not recognize its guiding significance for syndrome differentiation, applying it only for disease differentiation without using it for syndrome differentiation. Therefore, regarding rectal examination, apart from the author’s article, there is currently no relevant literature reported. It is hoped that more people will pay attention to this, conduct research in clinical practice, and promote its application.
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