The flu has been particularly bad this year. Some pharmacies have had trouble getting a hold of Tamiflu® suspension, a liquid form of a drug that is used to treat the flu in children and others who can’t swallow pills.
If your doctor has prescribed Tamiflu® capsules for your child, but your child is unable to swallow capsules, the CDC has provided a handy guide for how to mix the pills up with a liquid. There is a text version and also a PDF with pictures of the steps. The instructions mostly talk about using chocolate syrup, but you can also use corn syrup, caramel topping, light brown sugar dissolved in water, or another thick, sweet liquid.
If you are a pharmacist and need to compound Tamiflu® for patients, the manufacturer has a page with emergency compounding instructions.