Hi and welcome to HealingWell!
Have you tried eliminating alcohol completely and seeing if you GI distress disappears? I feel that if D and pain the day after drinking is your only problem, then it might be related to alcohol. Start by not drinking and seeing what happens. If your abnormal stools and pain doesn't go away then I would see a doc.
Digestive Advantage is basically a pill with a combination of probiotics and digestive enzymes. It worked great for me. It helps relived C and D and also gas. You can give it a try, unless you are allergic to sugar alcohols it should affect you negatively.
Unless you are handling animal feces and not washing your hands properly, I'm not sure your symptoms are related to the animal hospital. If your symptoms continue, however, you might want to see a doc and ask about
having a stool test to check for parasites. That seems highly unlikely to me unless you've traveled to 3rd world countries or somehow ingested animal feces.