How long should pain and swelling last after laparoscopy including diathermy and mobilisation of appendix?

Varies: Not quite sure what you are describing when you say diathermy and mobilisation of appendix. Im guessing you had a laparoscopic appendectomy. Pain and swelling after this procedure can vary depending on degree of inflammation and also every patient recovers at different rates. I tell patients that on average expect 3-4 days of pain that requires meds, but this can vary greatly.

Varies: The swelling and bruising after the surgery you list could last only a few days or it could take several weeks to fully resolve. If the symptoms are getting worse instead of better over time, you should see your surgeon.