Intestinal cleansing method. Most bad breath cases originate in the mouth and not in the intestine so using the intestinal cleansing method to fight bad breath is completely pointless. Brushing with cleaner If you have gone this far, then you should stop it immediately. Brushing with cleanser is dangerous, not to mention, poisonous. Eat low fat diet, fruits and vegetables. Fruits and vegetables such as celery, apply, carrot, cucumber, and alike clean your mouth naturally. Low diet food on the other hand keeps you away from those foods that contribute to foul breath. Also, avoid foods such as onion and garlic. They contain oil that when digested will be mixed with the bloodstream and produces bad breath. Clean your tongue. The best way to treat bad breath is to attack the area where bacteria are heavily breeding. Clean your tongue with tongue cleaner/scraper. This is the most effective way to remove the foul odor off your mouth. 5. Keep your mouth wet. Bacteria thrive on dry areas of your mouth. You should therefore not allow it to happen. Chewing sugarless gums can stimulate the production of saliva as well. Since meat, fish and dairy products can cause bad breath, a good brushing after meal is important to remove food particles from your mouth. Fibrous fruits and vegetables such as parsley, cucumber, apple, and carrots can help clean the teeth naturally. Often, cavities provide a venue for food particles to reside in the teeth that would further cause bad breath. 3. Nasal infection. This happens when a foreign object is stuck and infects in your child's nose. This creates discharge that is often odorous. 4. Poor oral hygiene practice. Children love to eat but hate to clean their teeth. These include liver failure which can cause a distinctive fishy odor, kidney failure which can give off odor that is urine-like, and chronic lung infection which also produces a bad-smelling breath. Throat, nasal, and mouth conditions can also cause bad breath. Canker sores, upper respiratory infections, bronchitis, mononucleosis, tonsillitis, strep throat, nasal discharge, and sinus infection are all associated to bad breath.