Constipation affects everyone from time to time, and can usually (but not always) be improved by changes in diet and exercise. You may have constipation if it is harder than usual to do poo, if your poo is harder than usual and if you go less often than usual. You may feel uncomfortable when you are constipated and feel the urge to go to the toilet, but be unable to pass much or anything solid. Sometimes you may only pass runny poo when you are constipated, as only liquid poo is able to get out around the hard poo.
Constipation does not cause health problems. No 'toxins' or poisons are absorbed from the large bowel. However, constipation can feel uncomfortable and passing hard, big lumps of poo can be painful and cause small tears of the skin around the anus, causing bleeding.
For information about constipation and how to avoid it or manage it have a look at these sites:
Better Health Channel (Victoria)
Gastroenterological Society of Australia
The information on this site should not be used as an alternative to professional care. If you have a particular problem, see a doctor or other health professional.