Anal swab examination is mainly used for the diagnosis of gastrointestinal infections, especially bacteriological dysentery, and is a means of examining patients who cannot pass stool. The anal swab test is performed by inserting an anal tube into the anus, rotating it a few times and then taking the stool from the anus. There is some pain in this examination method, especially for patients with rectal mucosal lesions or hemorrhoids, and in addition to pain, bleeding may even occur. Patients infected with toxic dysentery can present with high fever, low blood pressure, and altered mental status, but no diarrheal symptoms. At this time, it is necessary to use the anal swab method to collect stool specimens for routine stool and bacterial culture examination. If there are a large number of white blood cells and a few red blood cells in the stool, it can help clinical diagnosis of bacterial dysentery. Of course, a bacterial culture of Bacillus dysenteriae is required to confirm the diagnosis of bacillary dysentery.