Carefully, that is how. What you really need to watch for any stomach pains. Bleeding ulcers and even worse Perforated ulcers are a possible side effect when people quit taking this drug. It might not appear as stomach pain, it might appear as your back and/or ribs down to hip that feels the pain.
I had no idea about this but I woke one morning with a perforated ulcer, worst pain in my life. Spent a week in the hospital and now have a scar from sternum to below my belly button as they had to do emergency surgery to fix it. I never put two and two together about it being cymbalta but then one day years later my Uncle was real sick and I asked what was wrong and he said it was because he quit taking cymbalta as his insurance quit covering it, so I google cymbalta and find there are multiple other people who have had a perforated ulcer when they discontinued using it.
I was prescribed it for nerve pain in my neck from a disk that slight pinch or misalignment, not bulging.