Diarrhea means frequent defecation with loose or watery stools. TCM believes this symptom is mainly caused by an attack of exogenous evils, improper diet or yang deficiency in both the spleen and kidneys, which make water descend and cause dysfunction in the intestines. TCM divides the condition into the following six types:
• Damp cold type: Individuals present with diarrhea characterized by loose and watery stools. The stools are pale yellow and have a foul odor. Other accompanying symptoms are a bland taste in the mouth, fullness in the epigastric (the upper middle region of the abdomen), abdominal pain, intestinal rumblings and a poor appetite. There may be alternating chills and fever accompanied by headache, nasal congestion and general soreness.

On examination, the tongue is covered by thick white fur; the pulse is slow and hesitant.

• Damp heat type: Individuals usually start with abdominal pain followed by diarrhea, and pass formless and foul odor stools with great frequency. Other symptoms include intestinal rumblings, restlessness, thirst and a burning sensation in the anus.

On examination, the tongue is red and covered by yellow, thick and greasy fur; the pulse is rapid.

• Food retention type: Individuals have foul smelling diarrhea with sour and rotten vomit, fullness of the epigastric region, intestinal rumblings, abdominal pain that is diminished after fecal discharge, a poor appetite and fever.

On examination, the tongue fur is thick and greasy; the pulse is rolling. This is often due to eating unhygienic food or an improper diet.

• Spleen yang deficiency type: Individuals have diarrhea or
may just pass loose and soft stool. There is undigested food in the stool. Other symptoms include poor appetite, increased stooling frequency after eating greasy foods, abdominal distention, a dull pain above the navel, a sallow complexion, fatigue and general weakness.

On examination, the tongue is pale, enlarged and covered by white fur; the pulse is weak.

• Hyperactive liver qi attacking the spleen type : Individuals have abdominal pain and diarrhea following emotional disturbances. The abdominal discomfort will slightly diminish after defecation. Accompanying symptoms include fullness in the chest and rib sides, belching, loss of appetite, a bitter taste in the mouth, acid regurgitation, a sallow complexion and fatigue.

On examination, the tongue is pink with little fur; the pulse is taut.

• Kidney yang deficiency type: This is due to the kidney yang failing to warm the spleen. Individuals present with abdominal pain at dawn and then pass a loose stool. The abdominal pain is relieved after defecation. There is also coldness and soreness present in the lumbar area and knees. Distension in the abdominal region and aversion of coldness are typically present.

On examination, the tongue is pale and enlarged; the pulse is deep and fine.