Hi welcome to Health Care Magic.
First of all let me tell you drugs is not the solution for constipation
. If you start taking medicines for constipation, our body gets adopted to it and without medication you will find it difficult to have bowel movement. Best is to try natural methods such as drinking plenty of water, daily intake of fruits such as bananas, grapes etc. along with lot of vegetables in your daily meals.
Hard stools can scratch the inside of your bowels and cause bleeding and constipation can cause abdominal cramps.
However it is advisable that you consult a doctor to exclude any other pathology.