No, didn't help it. First time I have seen it though out of the few hatches that I have done. I have another one that hatched and it also has a small buldge in the butt, but not like the one pictured. Will it absorb the yolk?
Yep, it is the yolk sack. Leave it in the bator and let it rest. It should absorb that by the morning. I have one right now that looks the same way. The humidity spiked up drastically in my bator when the first seven chicks hatched and I think it just didn't give the eighth little guy enough chance to get the sack absorbed. BTW, mine spiked up to 87% and I have opened the vent plugs to get it down below 80%.
The chick might or might not absorb the yolk. I had one that had about 1 cm of yolk left. I pushed it in the naval and it stayed there. People have said that they have left it there or pushed it in. If it is too big then it might not absorb the sack.