Taking targeted drugs diarrhea may be due to drug reaction, indigestion, enteritis and other diseases, patients can be treated with general treatment and medication. 1. Drug reaction: during taking targeted drugs, it may cause severe diarrhea as well as vomiting and other adverse reactions. Patients should pay attention to a light diet, avoid stimulating food intake, increase the amount of water, if diarrhea is serious, you can use montelukast under the guidance of the doctor for treatment. 2. Indigestion: As the targeted drug will stimulate the gastrointestinal system, it may cause indigestion, thus causing diarrhea. Patients should avoid cold, greasy food intake, can be under the guidance of the doctor to take Pandolone, probiotics and other drugs to promote digestion. 3. enteritis: enteritis can also cause diarrhea, patients should avoid overwork, increase the amount of water to avoid dehydration, can be used under the guidance of the doctor Huanglianxin and other drugs for treatment. Taking targeted drugs after diarrhea is serious, you should contact your doctor in a timely manner, the use of drugs need to follow the doctor’s instructions, to avoid private blind use of drugs.