Hi Ms. Smita, Whenever you use an antibiotic, it is essential that you use lactobacillus along with the medication to avoid any unwanted intestinal side effects like diarrhea. Also, it is not true that every antibiotic causes this complication though this can occur in some people. As you are already taking Tinidazole in your medication you would not need any additional drugs. Please take sufficient fluids, avoid fruit juices during the course of treatment and consume buttermilk, low-fat milk, low fiber diet and vitamins. Hope this helps.