Constipation patients are weak due to yang deficiency and yin excess, qi and blood deficiency or phlegm-dampness during constipation. Patients with yang deficiency and yin excess are generally afraid of cold and indigestion, and all avoid cold food, so the coolness of sweet potato leaves just contributes to the yin excess of constipation patients. At the same time, eating sweet potato leaves during the illness of constipation patients will contribute to the exuberance of yin deficiency, so try not to eat other cold foods, such as sunflower, black dates, broccoli, Osmunda japonica, Codonopsis pilosula, buckwheat and water chestnut, while eating cold foods.