The Three Lions were hammered by 157 runs after responding to Sri Lanka's 256-8 with a meagre 99 all out.
The result has seen Sri Lanka level the five-match series at 1-1 ahead of next week's clash at Old Trafford.
"No excuses at all, it played a lot better than 99 all out - it was really poor and we've got to find some answers for the next game," Bell told BBC Sport. "We want to be positive to run as hard as we can and play proper cricket shots in that first 10 overs."
England and Sri Lanka play their third ODI at Old Trafford on Wednesday.