The effect of yam on constipation or diarrhea is relatively weak, so it can be consumed by both constipation and diarrhea patients. The occurrence of constipation and diarrhea includes dietary factors and disease factors, such as drinking less water, eating a fine diet and other dietary factors can lead to constipation, Crohn’s disease, intestinal tumors and other disease factors can have constipation symptoms; such as eating stimulating food, cold and other dietary factors can lead to diarrhea, enteritis, dyspepsia and other disease factors can have diarrhea symptoms. Constipated patients should avoid fine food, which can aggravate the symptoms of constipation; diarrhea patients should avoid green leafy vegetables and fruits, which can aggravate the symptoms of diarrhea. For yam allergy is not recommended for consumption, can cause allergic symptoms, such as itching, skin rash. It is recommended to consult a doctor to guide the diet according to the specific situation.