Lubiprostone
"For over twenty years I've had issues with my stomach. Mainly constipation in spite of drinking plenty of water and high fiber diet. I've relied on eating five servings of fruits and three veggies a day and of course lots of liquids. I've been seen by lots of specialists until recently I was prescribed Amitiza 8mg. I tried it for two weeks then tried the 24mg as instructed by my doctor and found that the lower dose works better. I'm able to defecate at least once a day now,  but I have experienced headache nausea and slight dizziness. Overall I do recommend it."