I'm wondering what is causing my belly button to move in and out?? i've been experiencing lots of gas, some cramping and diarrhea..

Possible Hernia: Based on your description, you might have an umbilical hernia, due to weakness in muscle layer under your belly button (umbilicus), which allows your intestines to bulge through, especially when you bear down (eg, cough, laugh, sneeze, move your bowels). Seek medical attention asap if you develop pain, redness, warmth, in the area, or bulge becomes firm and can't be pushed back down. Take Care!