Continuous horrible Hiccups during night

My mother is having some serious issues but I am not able to understand whom to consult for this problem. Whenever she tries to sleep at night or even in day she gets some horrible Hiccups (That sounds is very different not like the normal small one) and that will be in continuation, which causes she is not able to sleep at night. From the past year she is having this sleep issues and Hiccups issues we consulted to a general physician who suggested us to do some test and ultersound.after that she was diagnosed with gallbladder stone, in January this year,she was done with gallbladder removal surgery but still the issue is same and now it is worse. Can someone suggest me,to whom do I need to consult. What kind of disease it is ?