Need Information on a pill it has the letter M on one side and the number 4 on the other small white pill if you have any information on it that would be great. Thank you

It sounds like 4 MG Hydromorphone, which is a narcotic pain killer.

Have you looked for it here? Prescription Drug Information, Side Effects, Interactions - Drugs.com (http://www.drugs.com)

They have a pill identifier.