Diarrhea Constipation Bloating. Contact with animals / Gautemala

My Fiance is a Veterinary assistant.

Dec 10 She left for Guatemala to Spay and Neuter dogs.
Dec 15 She became sick. Nauseated / Throwing up / Diarrhea.
Diarrhea continued (Only Diarrhea). Regular bloating /cramping

Dec 18 She returned from Guatemala
Dec 18-19 . I get sick. My symptoms have mirrored hers, only occurring a few days after hers. (therefore I will only list hers)
Dec 22 Constipation. No bowel movements for 2-3 days.
Reasonably normal bowel movements
Dec 28 Frequent Diarrhea.

Things to note:

I became sick very soon (If not prior) to her arriving home. Either symptoms develop very quickly or over a period of time of several weeks. (I felt the trip was important to mention in case something could develop that quickly, although I am guessing it was transmitted prior to the trip)

I have an office job, and based on the time frames of getting sick, I presume this can be transmitted between individuals in close contact.

Neither of us had any negative indications on blood work or stool samples tested. Either it doesn't come up on these tests, or false negatives are very common.

We haven't had a fever or otherwise felt sick other than the bloating.