Po Chai Pills are a Chinese herbal medicine used to treat gastrointestinal problems such as stomach discomfort, nausea, vomiting, and diarrhea.

Their package is red and white with Chinese ideograms. The pills are quite inexpensive, I believe less than 3 dollars Canadian for a packet. Inside the large box are smaller red boxes and inside those boxes are phials of brown pills.

You are to swallow the whole phial with water. I find them quite effective for stomach discomfort and diarrhea, I normally take two phials.

There is a Japanese analogue called Sierogan but these are large and bad smelling/tasting. Po Chai Pills are coated so you don't have to deal with their scent or taste.