Zhou Kongchang, who was obese and weak, suddenly experienced abdominal pain and diarrhea, with slightly cold fingers and a very faint pulse. He was given Middle-Regulating Decoction, but after taking it, the diarrhea did not stop, and the reversal cold of the limbs worsened, with the abdominal pain becoming more severe. Upon re-examination, no pulse was detected, indicating that pudendal coldness had entered the kidneys. It was understood that the Middle-Regulating Decoction only regulates the middle jiao, which is quite different from the lower jiao. Therefore, White Unblocking Decoction was administered instead, and after one dose, he felt better.