hi. Thanks for your query. Noted the history and understood the concerns. A long history of diarrhea of about a month can have detrimental effects on overall health of a person. That can cause shaky vision, tremors of hands There can derangement of the thyroid functions causing all these three symptoms, thyrotoxicosis should be investigated for by blood tests. Flu like symptoms for the 2 weeks without an actual fever can be due to intestinal infection that caused diarrhea. Three days of vomiting on eating or drinking can cause GERD like symptoms causing gagging and burning feeling in the throat. I would advise you the following : Tests of stool for three consecutive days. Tests of blood for CBC, thyroid, liver, kidney functions and other tests including serum electrolytes. Ultrasonography of the abdomen. Upper GI Endoscopy and colonoscopy. CT scan of the blood. A course of an antibiotic, metronidazole and probiotics can help. Correction of dehydration and electrolyte imbalance can correct many of the symptoms that you have mentioned. Symptomatic and supportive management. Treatment of any medical diseases such as thyrotoxicosis needs to be done.