Can abdominal muscle injury/swelling be related to orthopedics or gastro-endology?

Well sure: In terms of what? Your abdominal muscles are usually separated from your joints. But during surgery you might have trauma to your abdomen i guess. But you need to talk to your docs about this. I doubt that when they do endoscopy they would hurt your muscles. But again if you are sedated you might get some bryuising of yur muscles while you are lying on the table.

See a doctor: Abdominal complaints can be either.....It is not uncommon to have an abdominal muscle injury that produces pain. Helping decide which doctor to see is generally a muscular strain does not bother you at rest. I would recommend you see your primary care physician to help you determine which route you should explore.