Diarrhea is loose or watery stool during a bowel movement more than 3 times per day. Patients may also experience other symptoms such as nausea, vomiting, stomachache, headache, fatigue, etc.
Gastroesophageal reflux disease (GERD) is a notable condition in which stomach acid leaks backward from the stomach into the esophagus, causing a burning sensation, chest pain, and vomiting.