A tiny parasite is making people very sick. It is spreading across the country. So far it has hit at least 17 states. And one of the main symptoms is explosive diarrhea.

The illness is called cyclosporiasis. A tiny bug called a parasite causes it.

Federal health officials counted 145 sick people as of June 16. Patients range in age from 5 to 86. About 61 percent of those sick are women. Twenty people ended up in the hospital. No one has died.

Most people first got sick around May 13. Cases go back to May 1.

None of the sick people had been out of the country. That means they ate bad food right here in the United States. Past outbreaks have been tied to fresh herbs, berries, and leafy greens.

Symptoms start about one week after eating the bad food. The main one is lots of watery diarrhea. It can hit hard and fast. You may also feel stomach pain, bloating, and nausea. You may run a low fever. You will feel very tired.

Most healthy people will not die from this. But it can drag on for weeks. A doctor can treat it with antibiotics. Go see one.

Every year from May through August, this bug tends to spread. Experts call it "cyclosporiasis season."

The CDC is still looking for the exact food that caused this outbreak. Until they find it: wash all fresh fruits and vegetables well. Every time. Before you eat them.

If you have had watery diarrhea for more than a few days, see a doctor. Tell them you ate raw produce.