For our study we are looking to recruit patients scheduled for abdominal surgery at Barnes Jewish Hospital. If eligible and enrolled, subjects will undergo sensory testing (a test of the sensitivity of the skin to hot and cold temperature and pressure) and complete questionnaires about their experience with pain, anxiety, depression and risk of substance abuse. They will also have a one-time blood draw for genetic testing, to look for a particular gene that is potentially associated with how we respond to pain medications and, potentially, with increased risk for addiction. After the surgery, patients will be assessed by the research team on day 1, week 1, week 4, week 8, and after 6 months with similar questionnaires to those that were completed pre-surgery. Patient satisfaction with their pre-surgical and post-surgical pain control will also be assessed by questionnaire.