BL27 (Xiǎo Cháng Shū, “Small Intestine Shu”) is the Back-Shu Point point of the Bladder Meridian. It is located in the sacral region, 1.5 cun lateral to the midline, at the level of the first posterior sacral foramen (S1). This corresponds to the level below the 18th vertebra in classical counting. It regulates the Small Intestine, separates the clear from the turbid, clears Damp-Heat from the Lower Jiao, benefits the lumbar region and legs, and dispels pathogenic factors like heat and cold from the three jiao.
In the sacral region, 1.5 cun lateral to the midline, at the level of the first posterior sacral foramen (S1). This corresponds to the level below the 18th vertebra in classical counting.
Perpendicular insertion 0.8 to 1.2 cun. Needling into the posterior sacral foramen can be done with an oblique medial and inferior insertion of 1.0 to 1.5 cun.
Regulates the Small Intestine, separates the clear from the turbid, clears Damp-Heat from the Lower Jiao, benefits the lumbar region and legs, and dispels pathogenic factors like heat and cold from the three jiao.
Lumbar and spinal pain, lower abdominal pain pulling to the testicles and spine, hernia pain rushing to the heart, urinary difficulty, reddish-yellow urine, dripping and difficult urination (lin syndrome), urinary incontinence, bloody stools, dysentery with pus and blood (red and white dysentery), tenesmus, hemorrhoids, leg swelling, headache, deficiency and exhaustion, unquenchable thirst with dry mouth, summerheat stroke, heat in the three jiao and bladder, cold in the three jiao, cold in the large and small intestines, diarrhea with undigested food, abdominal distention, borborygmus, female leucorrhea, heart vexation and shortness of breath, mouth and tongue dryness with inability to eat.
As the Back-Shu point of the Small Intestine, BL27 is a primary point for disorders of its paired Fu-organ. Its function of separating clear from turbid fluids makes it essential for treating urinary disorders like difficult, painful, or frequent urination, especially those with a Damp-Heat component. It is also a key local point for lumbosacral pain and sciatica, and its influence extends to treating dysentery and hemorrhoids, reflecting the Small Intestine's role in fluid and waste processing in the lower jiao.
Classical text; the translation was prepared with AI and is not clinical advice.
《針灸逢源》 Zhēnjiǔ Féngyuán — Sources of Acupuncture & Moxibustion, Li Xuechuan, 1815 · 卷四 · 經穴考正 · 足太陽膀胱經穴考 · Source: jicheng.tw ↗
小腸腧 在十八椎下兩旁。 開脊中二寸。 （針三分。 灸三壯）治淋瀝遺尿According to this text, BL27 lies on both sides below the eighteenth vertebra, 2 cun from the spine's centre; needle 3 fen, moxa 3 cones, and it records use for dribbling painful urination and enuresis.
《針灸資生經》 Zhēnjiǔ Zīshēng Jīng — Classic of Nourishing Life with Acupuncture & Moxibustion, 1220 · Source: Wikisource ↗
小腸俞 二穴．在十八椎下兩旁各寸半．針三分．留六呼．灸三壯It is located 1.5 cun on each side below the eighteenth vertebra, according to this text; BL27 is needled 3 fen, retained 6 breaths, with 3 moxa cones.
《備急千金要方》 Bèijí Qiānjīn Yàofāng — Essential Prescriptions Worth a Thousand Gold for Emergencies, c. 650 · 第二十 · Source: Wikisource ↗
治膀胱三焦津液下大小腸中寒熱，赤白泄痢，及腰脊痛，小便不利，婦人帶下方 灸小腸俞五十壯The text records that BL27 was moxibusted with 50 cones for cold and heat in the bladder, triple burner and intestines with fluids draining downward, red and white dysentery, lumbar and spinal pain, difficult urination and vaginal discharge in women.
《針灸甲乙經》 Zhēnjiǔ Jiǎyǐ Jīng — Systematic Classic of Acupuncture & Moxibustion, c. 256–282 · 卷09 · Source: Wikisource ↗
少腹痛控睪引腰脊，疝痛上沖心，腰脊強，溺黃赤，口乾，小腸俞主之The text records that BL27 was used for lower abdominal pain pulling on the testicles and radiating to the lumbar spine, hernia pain surging up to the heart, stiff lower back, yellow-red urine and dry mouth.
BL27 is one of 67 points on the Bladder Meridian. Nearby points:
BL27 (Xiǎo Cháng Shū) is located in the sacral region, 1.5 cun lateral to the midline, at the level of the first posterior sacral foramen (S1). This corresponds to the level below the 18th vertebra in classical counting.
BL27 regulates the Small Intestine, separates the clear from the turbid, clears Damp-Heat from the Lower Jiao, benefits the lumbar region and legs, and dispels pathogenic factors like heat and cold from the three jiao. Common clinical indications include lumbar and spinal pain, lower abdominal pain pulling to the testicles and spine, hernia pain rushing to the heart, urinary difficulty, reddish-yellow urine, dripping and difficult urination (lin syndrome), urinary incontinence, bloody stools, dysentery with pus and blood (red and white dysentery), tenesmus, hemorrhoids, leg swelling, headache, deficiency and exhaustion, unquenchable thirst with dry mouth, summerheat stroke, heat in the three jiao and bladder, cold in the three jiao, cold in the large and small intestines, diarrhea with undigested food, abdominal distention, borborygmus, female leucorrhea, heart vexation and shortness of breath, mouth and tongue dryness with inability to eat.
Perpendicular insertion 0.8 to 1.2 cun. Needling into the posterior sacral foramen can be done with an oblique medial and inferior insertion of 1.0 to 1.5 cun.
BL27 is a point on the Bladder Meridian (Zú Tài Yáng Páng Guāng Jīng).