Why do I have upper right side stomach pain at night?

Dealing with not fee­ling all empty after going to the bathroom and tummy trouble­s, I get it. Irritable bowel syndrome­, or IBS for short, commonly brings these issues. It's a lasting condition ne­eding ongoing care. Cutting out things that trigger it like­ dairy, spicy eats, and caffeinated drinks might provide­ relief. Staying active re­gularly also helps manage symptoms. Don't forget to drink ple­nty of fluids and de-stress, as these­ can worsen IBS. 

Your girlfriend might be experiencing acute appendicitis. Symptoms of this are sudden stomach pain on the lower right side with swelling. Appendicitis is when the appendix gets inflamed. If you think this is the case, you need to go to the hospital straight away because surgery is usually the only way to get rid of the inflamed appendix and avoid complications.

You're probably going through an infection. Your doctor is probably targeting different kinds of bacteria using azithromycin 500 mg in the morning and Flagyl 400 mg at night. Do not stop taking the medications even if you start feeling better. Prolong the treatment to ensure complete eradication of the infection. If you have any concerns or notice any unusual side effects, it's important to let your doctor know.

From your symptom, you may have a GI infection. One can consult a gastroenterologist or any general physician to receive proper diagnosis and treatment. For now, ensure that you stay hydrated and avoid the spicy food. In case the symptoms aggravate, see a doctor quickly.