Suggest Treatment For Persistent Loose Motion

hi my age is 37 years old.i visited my dentist for my treatment and he suggest me some antibiotic like augmenten 1000 mg for 7 days.i used that after using this my teeth infection was cleared but i got my stomach loose.I visited another doctor he asked me to use immodium capsole and probac sache.i used these and got temporarily relieve.after use of one week i remain normal but then after two days again i got same loose motions.I repeated this course with addition of flagyl tablet for 3 weeks. Now it is almost 3 months and i am unable to hab=ve my stomach normalise.I am unable to take any dairy product,of fat or fried thing or even citus fruit.i am taking only bread and tea in break fast and very light food in lunch or dinner.I need to pass stool after every three hours of taking food.Kindly guide me what is this problem,I am not alcoholic and i do not take coffe or any other norcotics