As with all laxatives, Bisacodyl (Dulcolax) should not be taken on a continuous daily basis or for extended periods without investigating the cause of constipation.
Prolonged excessive use may lead to fluid and electrolyte imbalance and hypokalaemia.
Intestinal loss of fluids can promote dehydration. Symptoms may include thirst and oliguria. In patients suffering from fluid loss where dehydration may be harmful (e.g. renal insufficiency, elderly patients) Bisacodyl (Dulcolax) should be discontinued and only be restarted under medical supervision.
Stimulant laxatives including Bisacodyl (Dulcolax) do not help with weight loss (see Pharmacologicas under Actions).
Patients may experience haematochezia (blood in stool) that is generally mild and self-limiting.
Dizziness and/or syncope have been reported in patients who have taken Bisacodyl (Dulcolax). The details available for these cases suggest that the events would be consistent with defecation syncope (or syncope attributable to straining at stool), or with a vasovagal response to abdominal pain related to the constipation, and not necessarily to the administration of bisacodyl itself.
The use of suppositories may lead to painful sensations and local irritation, especially in patients with anal fissure and ulcerative proctitis.
Patients with rare hereditary conditions of galactose intolerance, e.g. galactosaemia, and fructose intolerance should not take this medicine.
No studies on the effects of Bisacodyl (Dulcolax) on the ability to drive and use machines have been performed.
However, patients should be advised that due to a vasovagal response (e.g., to abdominal spasm) they may experience dizziness and/or syncope. If patients experience abdominal spasm, they should avoid potentially hazardous tasks such as driving or operating machinery.