Is there a good OTC suppository I can give my 7 year old? He can't keep anything down.

Not really. The only nonprescription nausea meds available can cause more side effects in kids. The best nausea med for kids is ondansetron, a prescription that dissolves under the tongue with only very rare side effects. Most kids will stop vomiting if they are given just a couple ounces of clear fluid every 20-30 minutes. No food until vomiting stops for at least 8-12 hours. If not working seek urgent care.