Interestingly, I once went to a guitar store and the owner told me of his trip to Mexico, how he'd gotten Montezuma's revenge, sick stomach, diahrrea, etc. The locals told him to take one shot of tequila upon waking up every day. He reported to me that he did just that, and his bad gut problem went away.
Later that month, one of my employees was in Mexico, called me and incidently to the business, he mentioned he had Montezuma's revenge. I immediately related the story about the music shop owner, and my guy tried the remedy, and it worked for him also.