Is it normal to get stomach cramps everytime i need to bm?

May be: Some light cramping before a bowel movement may not be abnormal. People with irritable bowel syndrome may have cramps with an urgent need to move their bowels and have diarrhea shortly after eating a meal. In normal people any cramping should be mild(gastrocolic reflex) and the bowel movement itself is usually normal and not very loose. An antispasmodic medication like bentyl (dicyclomine) can prevent cramps.