Stool thinning but normal colonoscopy results are mostly considered to be related to intestinal flora dysbiosis and irritable bowel syndrome. Usually the stool becomes thin, but the colonoscopy is normal, should consider the intestinal flora dysbiosis caused by the disease cause is relatively complex, may be related to the use of drugs, poor dietary habits, intestinal dynamics abnormalities, intestinal immune dysfunction and so on. Some patients are in a state of stress, irritable bowel syndrome, etc. can also lead to thin stools, but colonoscopy is normal. It is recommended that patients with thin stools but normal colonoscopy actively seek medical treatment, further improve the examination, clarify the cause of the disease under the guidance of a professional physician, and follow the doctor’s instructions for treatment. Pay attention to the rationality of daily diet and ensure balanced intake of nutrients.