Constipation, especially chronic, can be more than an aggravation, though; it can be unsafe. Large, heavy stools can stretch out the colon, irritate the colon walls, damage the good bacteria in the gut and produce toxins from wastes that have been sitting in the large intestine for too long. These troubles can trigger other health issues, such as body-wide inflammation, allergies, colon cancer and reduced emotional health.

Source: Gut check: How efficient or sluggish is your kids’ digestion? – The Washington Post