Glucose tolerance generally refers to the glucose tolerance test, after the glucose tolerance test generally does not cause diarrhea, if diarrhea occurs to consider is caused by nervousness, acute gastroenteritis, inflammatory bowel disease and other conditions. 1. Mental tension: If you have been in a state of emotional tension during the glucose tolerance test, the emotional factors may cause abnormal increase in intestinal peristalsis, which in turn causes diarrhea. 2. Acute gastroenteritis: If you eat unclean food after glucose tolerance test, it may induce acute gastroenteritis, resulting in diarrhea, accompanied by nausea, vomiting, abdominal pain and other symptoms. 3. Inflammatory Bowel Disease (IBD): It is a chronic non-specific inflammatory disease of the intestines, which can cause diarrhea, abdominal pain and other symptoms. If you have diarrhea after a glucose tolerance test, it is recommended to go to the hospital if the symptoms are severe or unrelieved.