What pain med is best used for people with cirrhosis?

You would want to ask your physician this question because he/she knows the particulars of your case where well meaning group members here could not possibly know. I did find this article for you and hope that maybe if your physician is reluctant to prescribe anything for your pain you can share this information.I hope it helps and you find yourself pain free. Good luck!
Here is the full link. I cut and pasted some highlights from it for you below.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2947971/

Opioids can be used safely to relieve pain and dyspnea, even in those with advanced liver disease (as well as advanced renal, pulmonary, and cardiac disease), and are preferred to nonsteroidal anti-inflammatory agents or other drugs, especially for moderate to severe pain.5,8 In our diverse and varied practices, we routinely use low doses of opiates such as intravenous fentanyl (with its short half-life) or oral or parenteral hydromorphone (which has less hepatic clearance than morphine) and believe that this can be done safely. The clearance of these drugs is reduced in patients with liver failure; thus, the initial dose may need to be lower, the interval between the doses may need to be increased, and such patients will need to be assessed on a regular basis.9,10 The effect of opioids can always be reversed with naloxone, but the effect of undertreated or untreated pain on patients (or the patient's family) cannot.

Effective palliative care and pain management involve 3 key components: (1) open and honest communication about the illness, options, and medically appropriate goal setting; (2) careful attention to symptom assessment and management; and (3) appropriate care of the family, including medical, psychosocial, spiritual, and other concerns. These components are completely congruent with the best practices in hepatology.
Long-acting opioids may be appropriate for chronic pain in patients with cirrhosis, once a safe and effective dose of short-acting opioids has been established. We disagree with the authors' recommendations for starting transdermal, continuous-release fentanyl for intractable pain (suggested in Figure 2 of their article as an acceptable “first-line” option comparable to low-dose oral hydromorphone), because introduction of a fentanyl “patch” would not be prudent until opioid requirements have been determined for the individual patient by titrating short-acting opioids to symptom relief.

Probably a pain med alone, that is not a combination product that contains acetaminophen