As of right now, there is no such thing as Diarrhea Coin. However, there are many different types of cryptocurrency, so it is possible that in the future there could be a Diarrhea Coin.
For those who are not familiar with cryptocurrency, it is a digital or virtual currency that uses cryptography for security. Cryptocurrency is decentralized, meaning it is not subject to government or financial institution control.
Coinbase is a digital asset exchange company headquartered in San Francisco, California. They broker exchanges of Bitcoin, Ethereum, Litecoin and other digital assets with fiat currencies in 32 countries, and bitcoin transactions and storage in 190 countries worldwide.
As of 2018, Coinbase had 25 million users. So if there were to be a Diarrhea Coin in the future, it is likely that you would be able to buy it on Coinbase.