How long does Dulcolax take to work in dogs

Bisacodyl should only be used to provide short-term relief from constipation.

If you are still constipated after using bisacodyl for five days, you should see your doctor.

Eating a healthy diet, drinking plenty of water and getting regular gentle exercise can all help maintain good bowel function.

Type of medicineStimulant laxative
Used forConstipation
Before some surgery and medical examinations
Also known asDulcolax®
Available asTablets and suppositories

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.

However, many people take laxatives when they do not need to because they believe that they are constipated unless they go to the toilet every day. This is not the case. A useful definition of constipation is going to the toilet less frequently than is normal for you, and passing hard stools (faeces) when you do go.

Bisacodyl works by encouraging the muscles in your bowel to move stools through your body. This helps you to go to the toilet. Tablets usually have an effect within 10-12 hours. Suppositories will take between 10-60 minutes to work, but usually have their effect within 30 minutes. Bisacodyl preparations are available to buy without a prescription at pharmacies and other retail outlets.

Bisacodyl is sometimes used to clear the bowel before a medical examination which requires the bowel to be empty. When it is used like this, you will be provided with a small supply of bisacodyl by your hospital or clinic.

To make sure this is the right treatment for you, ask for advice from a doctor or pharmacist before you start using bisacodyl if any of the following apply to you:

  • If you are pregnant, trying for a baby or breastfeeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.
  • If it is for a child under 10 years of age. This is because bisacodyl should only be given to children on the advice of a doctor or healthcare professional.
  • If you have severe pain in your tummy (abdomen) and feel sick (nausea).
  • If you have recently had any bowel or abdominal surgery.
  • If you are lacking in fluid in the body (dehydrated) or take 'water tablets' (diuretics).
  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.
  • If you have ever had an allergic reaction to a medicine. 
  • Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about bisacodyl and a full list of side-effects which you may experience from taking it.
  • Take one or two 5 mg tablets with a drink of water (do not take with milk). Bisacodyl tablets take about 10-12 hours to work; therefore, they are best taken at bedtime. Do not chew or break the tablets.
  • A suppository can be used instead of taking tablets. Use one suppository daily. It will take between 10-60 minutes to work and therefore should preferably be used in the morning. It will usually have its effect within 30 minutes. There are two strengths of suppository: 10 mg which is suitable for adults, and 5 mg which is suitable for older children (and younger children when prescribed by a doctor).
  • Bisacodyl should only be used for a short time. This is because your bowel can start to rely on this type of laxative to make it work rather than working on its own. If you are still constipated after taking bisacodyl for five days, you should speak with your doctor.
  1. Remove the suppository from the wrapping.
  2. Moisten the suppository with a little tap water.
  3. Using your finger, gently push the suppository into the back passage (rectum) as far as is comfortable.
  4. Remain still for a little while to help hold the suppository in place. It will start to work in about 20 minutes or so.
  5. Wash your hands after use.
  • Do not take indigestion remedies at the same time as bisacodyl tablets. This is because bisacodyl tablets have a special coating on them which is affected by antacid preparations. If you need to take something for indigestion, make sure you take it more than two hours before you take bisacodyl, or alternatively wait for two hours after you have taken bisacodyl.
  • A healthy diet containing fibre (whole grain breads and cereals, bran, fruit and green leafy vegetables) with six to eight full glasses of water each day and daily exercise are important in maintaining healthy bowel function.
  • You can read more about how to prevent or treat constipation in the separate leaflets called Constipation (for adults) and Constipation in Children.

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common bisacodyl side-effects - these affect fewer than 1 in 10 people who use this medicineWhat can I do if I experience this?
Feeling sick (nausea)Stick to simple foods
Loose or watery stools (diarrhoea)Stop using bisacodyl. This can be a result of taking bisacodyl unnecessarily or for too long
Tummy cramps or discomfortThis should soon pass
Suppositories may cause irritation to the bottomTry applying a gentle moisturiser to that area

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light. 

Never take more than the recommended dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital at once. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you buy any medicines, check with a pharmacist that they are suitable for you to take with your other medicines.

If you have any questions about this medicine ask your pharmacist.

Lactulose (brand names: Cephulac®, Kristalose®, Generlac®, Constulose®, Enulose®) is a disaccharide (sugar) laxative and ammonia reducer, used to reduce blood ammonia levels during liver dysfunction. It can also be used to soften the stools and to treat constipation.

Its use in cats, dogs, birds, and reptiles to treat high ammonia levels or as a stool softener is ‘off label’ or ‘extra label’. Many drugs are commonly prescribed for off label use in veterinary medicine. In these instances, follow your veterinarian’s directions and cautions very carefully as their directions may be significantly different from those on the label.

How is lactulose given?

Lactulose is given by mouth in the form of a liquid syrup or crystal granules. It may be mixed with food, but ensure the entire dose is swallowed by your pet. Measure the liquid form carefully. Cats generally do not like the taste of this medication, contact your veterinarian if you have trouble administering it. Make sure your pet has access to plenty of clean drinking water at all times while using this medication.

This medication should take effect within 1 to 2 days, and improvements in clinical signs should follow.

What if I miss giving my pet the medication?

If you miss a dose, give it when you remember, but if it is close to the time for the next dose, skip the dose you missed and give it at the next scheduled time, and return to the regular dosing schedule. Never give your pet two doses at once or give extra doses.

Are there any potential side effects?

The most common side effects include diarrhea, bloating, gas, and abdominal cramping, and these signs usually resolve over time. At higher doses, side effects may include low blood potassium levels and/or high sodium blood levels.

This short-acting medication should stop working within 24 hours.

Are there any risk factors for this medication?

Lactulose should not be used in pets that are allergic to it or in pets with intestinal blockage/obstruction. It should be used cautiously in pets with diabetes or with fluid/electrolyte imbalances and in pets that are pregnant or lactating.

Are there any drug interactions I should be aware of?

The following medications should be used with caution when given with lactulose: antacids, laxatives, neomycin, gentamicin, or warfarin.

Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking.

Is there any monitoring that needs to be done with this medication?

When used longterm, blood electrolytes may be monitored. In diabetic patients, blood glucose levels should be monitored. Your veterinarian may monitor your pet to be sure that the medication is working.

How do I store lactulose?

Store at room temperature between 20°C and 25°C (68°F and 77°F), in a tight container, and protected from heat or light. Do not freeze.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility.