Qianjin Fang (Essential Prescriptions Worth a Thousand Gold) states: In mountain streams, there are toxic insects. When people wade through the water, they feel as if attacked by "Shegong" (a toxic insect capable of shooting sand to cause disease) but see no physical object. The diagnostic method is as follows: Upon initial onset, there is aversion to cold, mild headache and eye pain, mental restlessness and vexation, trembling of the four limbs, stiffness and rigidity of the waist, back, and all joints, pain in both knees, or alternatively, a flushing sensation on the face with drowsiness. The condition is better in the morning and worse at night. Coldness extends from the hands and feet up to the elbows and knees. After two or three days, worms generate in the abdomen, eating into the lower part of the body. Sores appear around the anus, which are neither painful nor itchy, causing the patient to be unaware of them. If not treated urgently, after six or seven days, pus will discharge and ulcerate from the lower part; the worms will ascend to eat the five Zang organs (Heart, Liver, Spleen, Lung, Kidney). There will be intense heat, severe toxicity, restlessness, and uncontrollable diarrhea. By the eighth or ninth day, even a skilled physician cannot cure it. Upon suspicion, examine the lower part immediately. If the sore is bright red like cut meat, it is Yang Du (Yang Toxicity), which is most urgent. If the sore resembles carp teeth, it is Yin Du (Yin Toxicity); although slightly less urgent, it still requires attention. Both can be fatal within twenty days. To determine if this is Shui Du (Water Toxicity), boil five or six sheng (a unit of volume) of water. Add five sheng of chopped small garlic (Allium tuberosum var. angulosum), steep it in the water, do not let it become too hot, strain the residue, and use the liquid for bathing. If it is Water Toxicity, red spots should appear on the body. If there is no such reaction, it is not Water Toxicity, and other diseases should be treated accordingly.

Qianjin Fang formula for treating Shui Du (Water Toxicity).
Take leaves of plum or peach, crush them, and squeeze out approximately three sheng of juice. If using dried leaves, add a small amount of water to squeeze out the juice and drink it. For children who cannot drink, apply the juice to the nipple for the infant to suck.

Qianjin Yi Fang (Supplement to Essential Prescriptions Worth a Thousand Gold) formula for treating Water Toxicity.
Crush Xuan Shen Cao (Cocklebur fruit, *Xanthium sibiricum*) to extract juice. Take one sheng orally. Dip cotton in the residue juice and insert it into the lower orifice (anus) three times a day.

Qianjin Yi Fang, another formula.
Take a handful of Jiao Gu (Smartweed/Polygonum species), crush it, extract the juice, and take one sheng. Do not exceed three doses.

Qianjin Yi Fang, another formula.
Take a handful of Lan Cao (Indigo plant, *Isatis tinctoria*), crush it, dissolve in water, and wash the face, eyes, and entire body thoroughly.

Qianjin Yi Fang, another formula.
Take powder from the root of Da Mei Gen (likely *Rubus* species or similar medicinal root) and ingest it. Also apply to the lower orifice; if worms are present, use the juice. During summer, frequently add these herbal powders to bathwater. Throw a "Fang Cun Bi" (a square-inch measure, approx. 5-10 grams) upstream while bathing, without fear, as it also repels Shegong (toxic insects). For any bathing, throw a small amount of the herb into the basin. (This eliminates the toxicity.)