Eating instant noodles and room temperature watermelon does not usually cause diarrhea (diarrhea), but eating instant noodles and ice watermelon may cause diarrhea, abdominal pain, and other uncomfortable symptoms. If these symptoms occur due to improper diet, it is recommended to go to the hospital for a checkup to determine the cause of the illness and treat the cause. After eating instant noodles and ice watermelon, the gastrointestinal tract is stimulated by heat and cold, triggering acute non-infectious gastroenteritis. People at this time will have abdominal distension, abdominal pain, vomiting and other uncomfortable symptoms. People can take probiotics (such as bifidobacteria, etc.) under the guidance of a doctor when these symptoms occur, and take antidiarrheal drugs (such as montelukast, etc.) if the diarrhea is severe. When people suffer from acute gastroenteritis, it is recommended that they eat small meals, and the diet should be light and easy to digest.