Do you have any ideas why my drain output is still dark red?

Thank you for sharing your excellent question.  Remaining dark red blood may be a resolving hematoma underneath the skin portion of your mini-tummytuck.  This blood initially gels and can not be removed by the drain, but after 10-14 days the gel liquifies and can be seen coming out of the drain. Talk to your surgeon to ensure everything looks good with your healing and that you are progressing as expected. 

Persistent drainage needs to be evaluated by your surgeon. The purpose of drains is to collect fluids from the surgical site to aid healing. Drains are often able to be removed after 7 to 14 days. Your surgeon is most familiar with the details of your surgery and how you've been progressing through recovery.

Dark red blood in the drain at 13 days after tummy tuck may be a little hematoma that has liquefied and has finally drained.  If the drainage picks up or continues, see your plastic surgeon for an evaluation.  Usually at 3 weeks, drains are ready to come out.  Kenneth Hughes, MD, ABPS Board Certified Plastic SurgeonLos Angeles, CA