Recently, i started to eat less and do 100 sit-ups and bicycle crunch everyday . Everything seems fine, and i'm skinnier, it's been three months but when i go take a poop, i noticed that it is harder for me to poop when i kinda feel weak when i try to power up for the poop to come out and the poop is smaller and less than usual. ok dont laugh, but sometimes i power up really hard for the poop to come out, but it doesnt come out, and sometimes it does come out a little. and sometimes it's normal, eat lots of fiber from apple and drink water , everyday. And also i just got off taking anti-biotic acne pill, which i been taking for five months, i noticed the side effect is diahherea, but i have stop taking it for two weeks now, so when will i poop normal?What is wrong with me?