Gastric bypass with hiatal hernia repair done wed-off painkillers-vomiting (no nausea) a fecal like material-more coming out then going in-cause?

See your surgeon. The cause could be something normal during the post-op healing from a bypass, but it could also represent a problem. If you are not able to keep yourself hydrated, then you need IV fluids and medical attention. I definitely recommend contacting your bariatric surgeon for further evaluation.
Call your surgeon. If more is common out than going in, you could become dangerously dehydrated. This is an urgent matter. Hope this helps!