Came back from Mexico last week but still have an upset stomach what do you think it could be?

There are several possible causes for an upset stomach after returning from Mexico, including:

- Traveler's diarrhea: This is a common condition that affects people who travel to developing countries. It is caused by bacteria or viruses that are present in food or water that is not properly cooked or sanitized. Symptoms of traveler's diarrhea can include diarrhea, vomiting, abdominal cramps, and fever.

- Food poisoning: This is another common cause of an upset stomach after traveling. It is caused by eating food that is contaminated with bacteria, viruses, or parasites. Symptoms of food poisoning can include nausea, vomiting, diarrhea, abdominal cramps, and fever.

- Montezuma's revenge: This is a term that is often used to describe an upset stomach that occurs after traveling to Mexico. It is not a specific medical condition, but rather a catch-all term for any type of gastrointestinal distress that occurs after traveling to Mexico.

- Altitude sickness: This is a condition that can occur when traveling to high altitudes. It is caused by the body's response to the lower levels of oxygen at high altitudes. Symptoms of altitude sickness can include headache, nausea, vomiting, diarrhea, and fatigue.

If you are experiencing an upset stomach after returning from Mexico, it is important to stay hydrated and to eat bland foods. You may also want to take an over-the-counter medication to relieve your symptoms. If your symptoms are severe or do not improve after a few days, you should see a doctor.