The syndrome differentiation of diarrhea should include cold and heat, asthenia and sthenia and whether there exists deteriorated syndrome according to the causes of diseases, general symptoms and the property of stool. The common syndromes include diarrhea due to wind and cold, diarrhea due to dampness and heat, diarrhea due to improper diet, diarrhea due to asthenia of the spleen and diarrhea due to yang deficiency of the spleen and kidney, the first three of which can be seen in sudden onset of diarrhea while the last two can be encountered in chronic diarrhea.

The deteriorated syndrome includes impairment of both qi and yin as well as exhaustion of yin and collapse of yang, both pertaining to severe syndromes. Diarrhea due to wind and cold is commonly seen after catching cold, marked by thin stool with light colour and foam, borborygmus, relieved by pressure and warmth, and accompanied by exterior syndrome of wind and cold; diarrhea due to dampness and heat is commonly marked by urgent diarrhea, thin or watery stool with fetid odour, poor appetite, dysphoria, dark and scanty urine, red tongue  with yellowish and greasy fur, slippery and rapid pulse; diarrhea due to food impairment is encountered after improper feeding and diet, marked by abdominal distension and pain with the desire for defecation and relieved by diarrhea, sour and fetid stool with undigested food, thick and greasy fur, slippery and rapid pulse.

Diarrhea due to asthenia of the spleen has a longer course and is commonly marked by thin stool, intermittent onset, liability to postcibal diarrhea with light colour and without foul odour, accompanied by syndromes of asthenia of the spleen; diarrhea due to yang deficiency of the spleen and kidney is commonly marked by persistent diarrhea, or dawn diarrhea, thin stool with undigested food, accompanied by the symptoms of the syndrome of interior cold due to yang deficiency. Impairment of both qi and yin is commonly marked by diarrhea with excessive amount of stool, listlessness, hypodynamia, dry skin, sunken sockets of eyeball and fontanel, scanty urine, and anuria in severe cases; exhaustion of yin and collapse of yang is commonly marked by persistent diarrhea, watery stool, listlessness with weak breathing, cold limbs, thready and even fading pulse.