“What is the first-line treatment for diarrhea?”

Diarrhea will usually resolve on its own within about 24-48 hours. If it does not resolve, you may try an over the counter probiotic such as Align or lactobacillus. If the diarrhea continues, you may try Imodeum which is available at any pharmacy. Regardless, be sure to stay hydrated with sufficient fluids and see your physician if the diarrhea continues to persist.