My poop is always in strange shapes sometimes,it is in porous pieces with cracks,thin sausage shape , with some indigested food with mustard colour?

That's fine: This is of no real significance to your health. Life is hard enough without troubling yourself over the vagaries and imponderables of the lower intestinal tract. Much of this is a function of the gut flora, which is a "chaotic system", subject to strange fluctuations. The more you worry about this, the worse you'll feel. Hit the gym, eat sensibly, and be thankful for good health.