Anxiety
"I have been on Pristiq 50 mg for 2 days now.  I suffer from a host of illnesses, fibromyalgia, CFS, migraines, depression, etc. I have noticed a tremendous increase in my energy in just 2 days. However, I have been having severe abdominal cramps after eating (and I am eating light), but my psychiatrist advised me that the stomach pains should subside shortly.  I finally got through a day with a much more positive attitude."