I did have loose stools though one day in Zihuatenejo, after I was swimming and I swallowed some "water." The last supper in Zihuatenejo, I ordered a salad and big shrimp brochette. I did not even feel like starting the shrimp, but I ate it anyway. The next morning in Mexico D.F., I could barely eat any pancakes, and from then on until Puerto Angel, I felt really bloated and gassy all the time, and I could barely drink a beer. After a week, when I ate a meal one evening in Puerto Escondido, I got really sick the next day, with what I presume was the flu going around at the time. For the longest time, I thought that it was only my stomach acting up, and diet related.
The second day at the Zipolite beach, after being sick for three weeks, I ate two ice creams. Walking home, I was bent right over in pain from gas. After a dump at the hotel with big farts, I felt really cured, and fine from then on. I was subsequently reading about contagious diseases in my guidebook, and I narrowed what I had down to either Giardia (beaver fever) or Amoebic Dysentery. The main difference being that Dysentery has bloody stools and lasts forever, unless treated. As I was subsequently fine, I thought it was only Giardia, but recently, it's acting up again, with blood, so I am going to the clinic on Monday, February 12.