I have had a hernia operation but since then I have experienced pain in my side and testicle even after bowel movements what can I do?

Be reevaluated. Pain after hernia operation can be frustrating as well as debilitating. 1st be reevaluated by the surgeon to make sure hernia has not recurred. There are multiple options for working this up and adressing the pain including reoperation, removal of mesh or lysis of the affected nerves.