Swelling and bruising on inner thighs after tummy tuck, no liposuction performed. Is this normal? (photo)

It's common to have bruising in places where surgery wasn't performed secondary to settling.  However, make sure you plastic surgeon is aware.

The pressure garments usually used  after tummy tuck surgery will typically displace bruising from the actual surgery site to adjacent areas such as the thighs and pubis.  As with all bruising, these distant areas typically resolve over two to three weeks and leave no permanent marks.  Do not be surprised if the bruising works its way further down the leg as it resolves.

Indeed the inadvertent pulling on your drain could have caused the thigh bruising. This should resolve on its own. Show this to your plastic surgeon at your next visit.