Early manifestations of pyloric obstruction mainly include epigastric distension, vomiting of overnight food, visible gastric peristaltic wave, and water and electrolyte metabolic disorders in severe cases. 1. Early clinical manifestations of pyloric obstruction are often paroxysmal abdominal pain and mild abdominal distension, often aggravated after eating, accompanied by nausea, belching (hiccups) and other symptoms. 2. Repeated vomiting is a more prominent clinical manifestation of pyloric obstruction, and the vomit is usually the overnight food with rotten and sour odor and the amount of vomit is relatively large, and the above symptoms will be significantly aggravated in severe cases. 3. Because pyloric obstruction prevents the discharge of food from the stomach, there is a large amount of retention of gastric contents, which leads to dilatation of the stomach, so the patient’s examination will see the gastric shape (the outline of the stomach can be seen during abdominal visualization) and gastric peristaltic wave. 4. In severe cases of pyloric obstruction, the amount of vomiting is too large, resulting in the loss of large amounts of water and acidic gastric juice, thus causing water and electrolyte metabolism disorders, such as hypokalemia, hyponatremia and metabolic alkalosis, etc., and in severe cases, there will be symptoms of shock such as lethargy, limb twitching and even coma. Once the symptoms of pyloric obstruction appear, it is recommended to consult a doctor immediately and complete the relevant examinations in time in order to get timely treatment.