What Causes Fluid Discharge From Stitches Post Surgery?

Hi,
My father(60+) is recovering from a surgery that have got him some stitches. We notice some sort of crplear fluid coming out of wound. Doc have fixed it btpy draining and drying. However other two stitches go green and water like clear fluid started to come out.

Doc have re-stirched it so that it does not come out, and the internal tissues gel together.

Please suggest
1. Is there anything to worry about?
2. Is docs perscriptiin correct? What he should be doing?
3. How can the healing be faster?
4. Is it because internal stitches are leaking?
5. Percautionery what we can do to recover faster?

Please suggest.
Thanks and regards,