Hi there, Thank you for choosing healthcaremagic. Sorry to hear that your baby boy is suffering. As you mentioned in your question that your baby boy is having a fever from time to time and now has poor apetite and also has diarrhea. Teething doesnot cause fever or diarrhea, it may cause some irritability from the pain which can be soothed by giving him some cold teether toys or some keeping a giving him cold fruits that may help his pain. For his fever and diarrhea, he is probably suffering from an infection or gastroenteritis (stomach bug) for which he needs to see his pediatrician to be evaluated and to rule out dehydration. Till then, you can give him pedialyte or oral rehydration solution small sips frequently if his motions are very watery and his apetite is not good. Hope he feels better. Best wishes. Regards, Dr. Sumeet.