Brief Answer:
Chronic bacterial infection is causing your problems.

Detailed Answer:
Hello!

Thank you for the query.

Lets start from an explanation. Intestines are covered with bacteria. Lets call them good bacteria. This good bacteria protect intestines and whole body from other bacteria (lets call them bad bacteria). So the presence of good bacteria on the surface of intestines prevents bad bacteria from growing. Every person has individual type of good bacteria. Every person is resistant to some types of bacteria. Such resistance is build many years and created by an environment. In simple words, if you live for many years in the place where foods contain specific bacteria, you become resistant for it.
Now when you travel to other environment (like other city for example), you are in touch with bacteria previously unknown for you. So you are not resistant to those bacteria. If you also do not have enough good bacteria in your intestines, you may get an infection from this new, unknown bacteria.
Such chronic infection can cause loose stools, abdominal pain.

Now what you should do, is to improve good bacteria and fight the infection. To do that you should start probiotic intake and consider Rifaximine treatment (this should be prescribed by your doctor). If this wont help, stool test and stool culture test should be the next step.

Hope this will help. Feel free to ask further questions.
Regards.

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