There are many reasons for nausea with diarrhea, the more common include acute gastroenteritis, acute cholecystitis, heatstroke and so on. 1. Acute gastroenteritis: most patients have a history of unclean food and drink, when viruses or bacteria attack the gastrointestinal tract, can trigger inflammation, making the gastrointestinal mucosa in congestion, hematoma, and then produce a series of gastrointestinal symptoms, such as abdominal pain, diarrhea, nausea, vomiting, etc., in addition to fever symptoms. 2. Acute cholecystitis: acute cholecystitis in the attack, the patient mostly to the right upper abdominal colic or distension, as well as nausea and vomiting and other symptoms, a few may be impaired in the digestive ability under the influence of diarrhea. 3. Heatstroke: If prolonged exposure to high temperatures leads to heatstroke, there will be a large amount of potassium ions in the body with the loss of sweat, at this time it is prone to gastrointestinal dysfunction, the patient can also appear obvious nausea, diarrhea and other symptoms. There are many other reasons for nausea with diarrhea, it is recommended to go to the hospital as soon as possible to identify the cause of the symptoms, under the guidance of the physician treatment.