Constipation can be caused by a poor diet, not drinking enough water and not going to the toilet as soon as you feel you need to. Pregnancy, a lack of exercise or movement (such as being ill in bed) and some medicines, including some painkillers, can also cause constipation.
This is a companion discussion topic for the original article at https://patient.info/medicine/sodium-picosulfate-dulcolax-pico-citrafleet-picolax