Hi.. Can understand your concern.. As per your complain it seems that you have symptoms of Gastro-oesophageal reflux disease causing BURNING MOUTH SYNDROME when the acid from the stomach reflux back into the stomach and mouth leads to burning sensation in tongue due to continuous exposure with strong stomach acid.. Diarrhoea also occurs as a result of deficient stomach acid which disturbs the normal digestive function leading to loose motions and diarrhoea.. I would suggest you to consult an Oral pathologist and get evaluated and in case of acid reflux you need to consult a gastroenterologist and get an endoscopy done to rule out the exact cause of it.. In case of reflux Proton pump inhibitors like Pantoprazole, omeprazole, Rabeprazole can be taken empty stomach along with antacids like digene or gelusil half an hour before meals can be relieving.. To control diarrhoea you need to take Furazolidone containing medications like Lomofen. Drink plenty of water to maintain hydration and it helps in dilution of the acid.. Prevent spicy and acidic foods.. Take more of probiotics like Yoghurt. For burning sensation in mouth you can suck on ice pops.. Drinking cold water and gargles with cold water can be relieving.. In case if you experience dry mouth Saliva substitutes containing methyl cellulose can be instilled in mouth.. Sugar free chewing gums and sour candies can be taken to stimulate saliva flow.. Hope this information helps.. Thanks and regards.. Dr.Honey Nandwani Arora..