Yesterday I Returned From A 3 Week Trip To South

Yesterday I returned from a 3 week trip to South Africa. I was fine during the trip. The flight home was very long (approx. 33 hrs over three separate legs of travel). I did not feel ill during the flights. SInce I got home, I have intermittent stomach cramping (like premenstrual cramps though I am 65 yrs old). I have also experienced frequent loose stools. I feel bloated. I suspect my body is adjusting to the long flight and I am adjusting to a completely different environment and time zone. Thoughts?