I've been taking pentasa with food but last night I took it 3 hrs after eating, on an empty stomach, and I was nauseous and dizzy for an hour. then later, my toes on both feet felt numb. then I read that it's better to take with food, esp. if you get nauseous when taking it. I don't know whether the numbness was from a "higher" dose of pentasa in my blood taken on an empty stomach, or if it set off a chain reaction with the nerves in my abdomen, but it was definitely pentasa related. as I sit here now, the tops of my feet feel hot. I'm taking vitamins, so I don't think it's my B levels, and it wasn't one of the side effects listed that I've found. maybe there's a subset of patients who do get a reaction, but it's not public knowledge or they don't know why.