The invention provides a traditional Chinese medicine composition for treating a diarrhea-dominant irritable bowel syndrome. The traditional Chinese medicine composition comprises fructus evodiae, hairy euphorbia, bighead atractylodes rhizome, immature bitter orange, gallnut, smoked plum, fructus galangae, acorus calamus L., pollen pini, white hyacinth bean, liquorice, lotus seeds, fructus psoraleae, catechu, changium smyrnioides, radix saposhnikoviae, betel nuts, fingered citron, agilawood, semen coicis, polygonum aviculare, rhizoma alpiniae officinarum, coptis roots, cortex ailanthi and radix tinosporae. Compared with western medicine for treatment, the composition has the advantages that the composition is good in curative effect, takes effect rapidly, has no toxic or side effects, does not result in tolerance, and can effectively relieve illness of a patient, and the recurrence rate is low.