Boro were second best all afternoon and succumbed to goals from Tommy Smith (2), David McGoldrick and Aaron Mclean at Portman Road.
Mowbray said: "It was a poor performance from us and there are no excuses.
"We came here in a positive mood thinking we could get three points, hoping to push on and put pressure on the top two again.
"Now we're looking for a reaction because wasn't good enough.
"We've lost four on the bounce and we either curl up and die or come out fighting, to show our credentials for a top-six place. We've got a great chance to do that this week with matches against Barnsley and Leeds.
"Ipswich are a hard and honest team to play against. We got frustrated that they weren't letting us move the ball around, because our game is all about the fluency of our passing.
"But we're better than we showed. We have to roll our sleeves up, get back to working hard on the training pitch and get back to winning ways.
"You have to put these games behind you."