I am also 5'8" tall with 37" hips. The medium was too tight for me, but would be great for someone younger with a fabulous hip/thigh area. I got the large in the sangria and it is perfect. The length is perfect. For those not so tall, you can easily roll up the waistband.
The charcoal in large was still way too tight for me. BTW - the charcoal does not need a slip underneath.
Would be 5 starts if it was not made so small.