Breathing carbon monoxide causes headache, dizziness, vomiting, and nausea. Nausea, vomiting, and diarrhea may also occur. Symptoms typically include abdominal cramping, diarrhea, vomiting, and fever. Gastrointestinal symptoms, such as vomiting or diarrhea may occur. Nausea, vomiting, and severe itching may also occur. Nausea, vomiting, and intoxication are symptoms of ingestion. Symptoms include diarrhea, vomiting, and anorexia. Adverse responses include difficulty swallowing, chest pain, vomiting, and nausea. Migraines are often unilateral, pulsing headaches accompanied by nausea or vomiting. It may induce intense vomiting and occasional diarrhea. Malaise, muscle pain, headache, vomiting, and diarrhea occur frequently. Gastrointestinal perforation results in severe abdominal pain intensified by movement, nausea, vomiting and hematemesis. Intestinal disturbances are common, including loss of appetite, nausea, vomiting, and constipation. The initial signs are gastrointestinal, including nausea, vomiting, and diarrhea. Allergens frequently produce symptoms such as diarrhea, rashes, bloating, vomiting, and regurgitation.