Can you please further elaborate the problem? What are the symptoms? Is the stomach infection associated with the chronic alcohol intake and liver function deterioration? Did you doctor mention the diagnosis? What are the investigations done?
You can try Ciprofloxacin and Metronidazole combination. The other combination which works as good is Norfloxacin and Metronidazole. The symptoms may also occur because of the eatables you had with the whiskey like salads etc.
Getting a stool examination would be prudent. If the symptoms do not abate, consult your physician. Drink plenty of water and electrolyte solution to keep yourself properly hydrated and preventing electrolyte disturbances.
Hope this helps.
Please feel free for your follow up questions.
You are welcome.
Best wishes and kindest regards.