Our stool contains about 75% water. It is estimated that on an average about 200 ml water is lost in the stool from the body which prevents hardening of the stool. In constipation, the opposite occurs. More water is removed in the small and large intestine leading to hard stool. Constipation occurs in many reasons if people do not drink adequate amount of water or fluid. Fibres are food which are not absorbed in the intestine and have a tendency to retain water. So, taking foods high in fibre makes the bulk of the stool and keeps the stool soft. Another problem that causes constipation is unnecessary holding of stool. This leads to more absorption of water as stool stays there for more time and the reflex which leads to passage of the stool in the last part of the large intestine (sigmoid colon, rectum) is also inhibited. Usually, as the rectum is filled up such reflex called mass peristalsis occurs which drives the whole stool down towards anus. The opening of the anus is under our control. But, if we ignore this reflex again and again, the reflex does not work well in future. This results in chronic constipation as more water is absorbed from stagnant stool.