The causes of diarrhea in the elderly include intestinal space-occupying lesions, intestinal dysfunction and systemic diseases, etc. Diarrhea can be stopped by taking bifidobacteria, symptomatic treatment with montelukast, metformin, methimazole, surgical treatment and other active treatment of the primary disease. 1. Intestinal space-occupying lesions: such as colorectal cancer, etc., which may lead to diarrhea, at this time can be examined through colonoscopy, and surgical treatment can be carried out if necessary. 2. Intestinal dysfunction: due to the imbalance of intestinal flora, the elderly may cause diarrhea, at this time, you can take montelukast to protect the intestinal mucosa, supplement probiotics such as bifidobacteria, etc. to relieve diarrhea. 3. Systemic diseases: such as diabetes, hyperthyroidism and other systemic diseases may also lead to diarrhea, at this time diabetic patients can be treated with insulin, metformin and other drugs, hyperthyroidism can be used to treat primary diseases such as methimazole and other drugs. If the elderly have diarrhea, you can seek medical treatment in a timely manner, the relevant drugs should be used under the guidance of a doctor.