Constipation, in most cases, is an outcome of faulty eating habits and lack of exercise. Normally, as the food gets digested, it passes from stomach through the small intestine into the large intestine. Most of the water from the remaining undigested food gets reabsorbed in the large intestine. If the large intestine (colon) absorbs too much of water due to slow movement of the undigested food, the stools that are formed become dry and hard. Additionally, if the movement is slow enough to cause an urge for stool less than thrice a week, it results in constipation.

Some of the common triggers of constipation include:

Poor intake of fluids - drinking less of water and other fluids

Less fiber in diet

Sedentary lifestyle - not much of activity

No exercise

Ignoring the urge for stools when there is one

Change in routine, travelling

Pregnancy and childbirth

Abuse of laxatives - Laxatives lead to dependence in the long term because the colon begins to rely on the laxatives for a normal bowel movement

Medications like certain painkillers, iron supplements, diuretics, antidepressants, etc.

Pain in the anal region due to fissure or piles (hemorrhoids) can lead to suppression of the urge for stools later leading to constipation.

Hormonal problems like hypothyroidism

After an abdominal surgery

In case of constipation in children, the following must be considered:

Switching from breast milk to bottle milk or solid meals

Toilet training anxiety

Ignoring an urge for bowel movement

Hirschsprung's disease (rare condition where the child has a nerve cell defect from birth that affects communication between the brain and bowels)

Some rarer causes of constipation include:

Tumor of the bowels

Lead poisoning

Lactose intolerance

Spinal cord injury that has damaged nerves reaching the intestines