Both pregnancy and gastroenteritis may cause nausea, vomiting, and anorexia. The vast majority of nausea, vomiting, and anorexia caused by pregnancy are relatively severe in the morning, while gastrointestinal reactions caused by gastroenteritis may occur regardless of the time of day. In addition, pregnancy will have a clear history of menopause, while gastroenteritis does not necessarily have a history of menopause. Gastroenteritis can cause discomfort or pain in the lower abdomen and stomach, while normal pregnancy does not cause pain. The differential diagnosis can be made by blood test or urine HCG test. After pregnancy, urine HCG will show positive reaction, while gastroenteritis will not show positive reaction by urine HCG test, and gastroenteritis may show positive result by stool routine test.