Hi and thanks for the query, Its an important considerations to carry out a detailed assessment of these symptoms. The causes of these symptoms could be infectious, organic or functional. With the coating of the tongue first. The commonest cause of a white coating in the tongue is oral candidiasis. This however needs to be appropriately inspected before a clear diagnosis is made. Other causes like oral cell leukoplakia are seen under particular circumstances. Past medical history, characteristics of the pain and associated symptoms are important considerations that shall be studied in the diagnostic process. Stool examination and culture with sensitivity tests, blood tests, abdominal scans and endoscopy could be useful Other non organic causes like irritable bowel syndrome could be considered. But this diagnosis is only made when all other causes have been excluded. A recent change in diet is very important. Eating at regular times, identifying foods that disturb the individual and avoiding them, drinking a lot of water, eating a vegetable rich and fruit rich diet and doing exercise on its own can do so much good. I suggest in case of persistence of symptoms, to consider a consultation with a gastroenterologist. Thanks and hope this helps, Luchuo, MD.