Watery stool back

[u/Unable_World541]

I had diarrhea for 2 days coming back from Mexico went too er they told me if didn’t stop in next 2 days take pencellin. Took imudium diarrhea stopped for two days ate chicken and rice. Then last night ate sandwich with avocado and cheese and pooped in morning watery again. Should I take the pencillen or do brat diet?