Every child has a gland in the nose and throat that produces mucus. Normally, this mucus does not cause too much problems, dripping behind the throat and eventually entering the stomach. But when the glands begin to overproduce, or the mucus becomes abnormally thick, your child will have a postnasal drip that can sometimes make your child's stomach uncomfortable.

Postnasal Drip
There may be many reasons for sinus drainage and subsequent stomach pain, so it is usually best to make an appointment with a doctor . Anything from the common cold to allergies to sinus infections can encourage these glands to secrete too much mucus. Even objects on the child's nose increase the production of mucus. Uncontrolled drainage can cause stomach upset and can cause sore throat and persistent cough.
Fluid
When you have sinus drainage, you need to inject more fluids. Your child can sometimes calm down nausea. The extra liquid helps to dilute the mucus, which prevents many complications. The Cleveland Clinic points out that clear liquids are the best, but those that add sugar and sugar can calm the abdomen better than others.
In addition to relieving nausea, extra fluids can also prevent dehydration if the stomach is uncomfortable and the child vomits. But don't give your child too much liquid at a time. It can over-extend the stomach and make this symptom worse.
Rest
Like fluid, rest can greatly improve your child's stomach pain. But don't just lie to your child. Instead, raise your head about 12 inches higher than his feet. This can reduce nausea and prevent excess mucus from flowing down the back of the throat.
Drugs
Basic salicylic acid can treat diarrhea and upset stomach. However, it is not recommended for people under the age of 12. It is also not recommended when children or adolescents deal with flu or chickenpox. The National Institutes of Health warned. Salicylates in these drugs can cause Reye's syndrome, a disease characterized by swelling of the liver and brain.