How does senna work?
Senna stimulates the muscles in the gut, helping to move stool through the bowel more quickly and relieve constipation.
What is senna used to treat?
Senna is commonly used for:
- Short-term relief of constipation
- Bowel clearance before medical procedures (e.g., colonoscopy)
- Occasional use in people with chronic constipation
Who can take senna?
Senna is suitable for most adults and children over 12 years old. In some cases, a doctor may prescribe it for younger children.
Who might not be able to take senna?
Senna may not be suitable if you:
- Have a blockage in your bowel (intestinal obstruction)
- Have severe dehydration
- Have ulcerative colitis or Crohn’s disease
- Have had an allergic reaction to senna or similar laxatives
Can I take senna if I’m pregnant or breastfeeding?
Senna is sometimes used during pregnancy and breastfeeding, but it should only be taken under medical supervision.
What if I miss a dose?
If you forget a dose, take it as soon as you remember. If it’s close to your next dose, skip the missed one—do not take two doses at once.
How effective is senna?
Senna is highly effective at relieving constipation, usually working within 6 to 12 hours.
What should I do if I take too much?
Taking too much senna can cause diarrhoea, stomach cramps, and dehydration. If you experience severe symptoms, seek medical advice immediately.
What dose of senna is usually taken?
- Adults and children over 12: 7.5mg to 15mg once daily, usually at bedtime
- Children aged 6-11: As prescribed by a doctor
Your doctor will determine the correct dose if you need to take it regularly.
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What are the side effects of senna?
Common side effects include:
- Mild stomach cramps
- Diarrhoea (if taken in high doses)
- Discolouration of urine (temporary and harmless)
Long-term use may lead to dependency, electrolyte imbalance, or reduced bowel function. If symptoms persist, speak to your doctor.
How should I take senna?
Senna is taken as tablets, capsules, or liquid, usually once a day before bedtime to work overnight.
When should senna be taken?
Senna should be taken at night, as it usually works within 6 to 12 hours.
What are the brand names for senna?
Senna is available as a generic medicine, but some branded versions include:
- Senokot
- Ex-Lax Senna
Final thoughts
Senna is an effective short-term treatment for constipation, but it should not be used long-term without medical advice. If symptoms persist, speak to your doctor about alternative treatments.
