I Have Been On 100mg Of Methadone For 6 Years

I have been on 100mg of Methadone for 6 years through a clinic.. I am having problems with Gerd and the last 72 hrs my middle upper stomach through my back has been hurting severely. Couldn't take it anymore and went to ER last night. They did all kinds of test one came back with blood in stool and they believe it's my gallbladder anyway I have my appt finally tomorrow with a gastrointologist tomorrow after waiting 2 months. Sorry my ? Is last night they gave me Ultram for pain. I had Morphine while I was at ER . People are saying that the 50mg Ultram will put me in withdrawals and some say it won't like the Pharmasist and Dr from last night. I only have 12 50 mg of the Ultram and I would only take it if I got in the pain I was in the last 72 hrs but last night was very bad, I keep getting contrdicting answers. What is your opinion ?