However, Mick McCarthy's side broke the deadlock just past the half-hour mark and went on to double their lead, the hosts unable to conjure up a response.
"First half-hour, I didn't have a complaint," Coleman told the Sunderland Echo. "There was some good stuff and we should have gone 1-0 up.
"That all important first goal that we don't recover from. The second goal, seconds before half time, it is incredible to again concede like that. It knocks the life out of you, of course it does.
"Second half, we tried, we looked naive in certain situations. If you look at Ipswich they have a lot of boys who know the division, they are streetwise. We are sometimes naive.
"We have shown some good stuff to build on but we have to stop letting teams off the hook and gifting teams goals. We never get easy goals, why are we giving the opposition goals. We can't do that otherwise we will never get away from where we are."
The result leaves Sunderland 23rd in the Championship table, two points from safety.