Do you recommend the use of Arnica post tummy tuck?

Yes  , you can use the arnica gel for the bruising area, It helps the decreasing of the bruising. You can use it 2-3 times a day. You can also do massage slightly with the arnica gel.

Thank you for sharing with us your question.
After a plastic surgery it’s very important to check with your Surgeon any medication or concern as patient you have.
I never recommend to my patients Arnica but is not for a bad feedback, is just as a homeopathic medicine most of my patients wants something more strong, if you used Arnica before and you had this amazing results speak with your Surgeon and share with him/her this as well. 
Best of luck,
Dr. Quiroz!