text: how common is diarrhea during early pregnancy?   in my first trimester, i had diarrhea instead of morning sickness.  and then came the constipation.  make sure to eat lots of fiber, you will need it-apples and whole grain pasta, bread, and rice.  and as many fruits, veggies, and glasses of water as you can stand.  that was the first and only time in my life that i was constipated.  it was awful.