Taiyang disease, on the second or third day, the patient is unable to lie down and only wants to sit up. There is a knot in the heart region, and the pulse is faint and weak. This indicates an underlying cold condition. If purgation is mistakenly applied and the diarrhea stops, it will lead to thoracic accumulation. If the diarrhea does not stop, purgation is repeated on the fourth day, resulting in diarrhea with fever.