Original Text
When in tai yang disease, and the external pattern is not eliminated, and there was repeated precipitation, consequently there is ceaseless diarrhea, fullness below the heart, exterior and interior not resolved, gui zhi ren shen tang governs.

Explanation
These symptoms are Spleen yang vacuity.  In addition, the exterior is not resolved and the exterior and interior are both cold.  External symptoms are not resolved with symptoms of fever and aversion to cold.  There is Spleen yang vacuity, causing the ascending and descending function to not be normal.  Clear yang doesn’t ascend, resulting in ceaseless diarrhea.  Turbid yin doesn’t separate leading to a hard fullness below the Heart.  The formula uses Li Zhong Tang to warm the tai yang vacuity cold, adding gui zhi so as to resolve the tai yang exteriorly.

Late Stage Measles and Diarrhea
Shen Yan Nan case: Girl, about 3 years old, her measles had already resolved, however her fever hadn’t receded and was 39 degrees Celsius.  Whether or not she had a headache or aversion to cold one will know.  [She was experiencing] diarrhea over 10 times per day and her feces were yellow and watery.  Her pulse was rapid and regular [didn’t skip a beat] and her tongue was still normal.  Examination of the rash revealed heat toxin that had not completely disappeared.  She was prescribed Ge Gen Qin Lian Tang plus shi liu pi.  After taking [this formula], her temperature increased to 39.5 degrees Celsius, and the ceaseless diarrhea remained.  Her feces had a smell that wasn’t aversive or foul.  The author pondered over this matter over and over.  The child’s complexion was fatigued and tired.  [He felt] it was correct to prescribe Gui Zhi Ren Shen Tang, keeping the addition of shi liu pi.  After one dose, her diarrhea decreased.  After another dose, the heat retreated and the diarrhea stopped.

Comments
After measles, the evil had not finished and was stuck in the interior, jointly with hot diarrhea.  Because the exterior and interior were both cold, this lead to diarrhea that was not foul or dirty but instead had heat symptoms of a scorching hot anus, a rapid and regular pulse; this is supposed damp injury.  The complexion was tired, with over ten episodes of diarrhea in one day.  Ge Gen Tang was given resulting in treating cold with cold, like covering ice with a layer of snow, the yang qi floated upward and internal heat appeared suddenly.  It was appropriate to use Gui Zhi Ren Shen Tang to warm and move the exterior and interior.  To defend against loss from diarrhea, he added shi liu pi and used an astringent decoction to stop the diarrhea.

   [Carefully chosen medical examinations due to cold injury], main volume, College Printing House ,pg 140-142.