Constipation and Weight Loss Surgery

Whilst not uncommon following weight loss surgery, is not something we tend to feel comfortable in speaking about. It is however important to feel you can speak freely about this topic to your dietitian and bariatric GP, as it is an important issue that needs discussion and management.

What is Constipation?

Naturally when you are eating less food after weight loss surgery, it becomes normal for less to come out. This does not mean you are constipated. Constipation is not only about how often you go, but rather how you go and the consistency of your stool. After surgery it can be common not to open your bowels for three or four days. Going less often, but with ease, is fine and not defined as constipation. However, if you feel you need to go but can’t, or you are getting a sore tummy, or you need to strain to go, this is likely constipation, even if you are able to pass stools daily.

Looking at the Bristol Stool Chart below, our goal is to aim for a Type 3 or 4, however this depends on your stage post-surgery. Type 1-2 suggests constipation and that you may need extra fibre, fluid, or physical movement. However, it is important to discuss this in detail with your dietitian, as these recommendations may not be appropriate or possible for you during your early stages of recovery.

Bristol Stool Chart



Managing Constipation in the Early Post Surgery Phases


If you are constipated, firstly reflect on your fluid intake. One and a half litres per day is a good goal, but can be challenging in the early phases. Remember to sip, sip, sip and chat to your dietitian if you are struggling and need more ideas to keep well hydrated.

It can also be useful to reduce your intake of caffeinated beverages if you are including these.


Add in as many natural fibre sources as possible to your diet including fruits, vegetables and legumes. In the fluid stage these can be in smoothies or soups, as long as these fluids are then blended until thin enough to get through a straw. When on the smooth puree phase, these can be mashed or blended to a smooth texture, similar to the texture of a smooth, mashed potato.

Fruits high in sorbitol may be the most beneficial, as sorbitol has a very gentle softening effect. Examples of fruits high in sorbitol include apples, apricots, avocado, nectarines, peaches, plums, pears and prunes (including their juice varieties). Be sure to be mindful in choosing the appropriate textures of these depending on your recovery phase.

Fibre Supplements

We often recommend Benefiber or Feel Good Tasteless Fibre, as these are suitable to use during the fluid recovery phase and beyond. However, you do need to be including at least one and a half litres of fluid each day for them to be effective, or else it may worsen your constipation. Benefiber and Feel Good Tasteless Fibre are not laxatives, meaning they don’t have an instant effect. They are fibre powders that help to draw and hold water in your stool to keep it soft. Therefore, if you are not drinking enough, it can dry out your stools, making them harder to pass. Ideally, these supplements needs to be included regularly over a long period of time with ongoing adequate fluid intake to be effective. Again, try to sip, sip, sip fluids when you are not eating.

Some may find the following DIY homemade fibre supplement useful.

75g Allbran
250g Apple Puree or apples, pureed 75g prunes, pureed
50ml orange juice

Blend all ingredients, adding more juice if required. Store in the fridge or freeze in ice cube trays. Include a tablespoon at a time or as ice cube sized serves. Include 1-2 serves daily.


Many of our patients have used laxatives such as Coloxyl, Dulcolax or Movicol. However, it is essential that you have a chat to your Bariatric GP (or pharmacist) before commencing these to determine the best option for you, including the potential use of suppositories and/or enemas. The effectiveness of laxatives can be highly individual and require some trial and error, which is best supported by a medical professional.


Consider using a foot stool whilst sitting on the toilet. Placing it underneath your feet creates a much more natural position for the body, hopefully creating some ease.

It’s important to know that these suggestions may not work for everyone Each person’s bowel is a little different, and what works to relieve constipation for you can be a bit of trial and error. If you’re concerned about your bowel function, or it’s causing pain, please contact your bariatric GP.


Managing Constipation Long Term

If you are experiencing constipation on a regular basis a year or two after surgery, try the following:

  • Ensure you’re getting 20g or more of fibre (including sorbitol sources) in your diet and one and a half to two litres of water daily.
  • Include regular exercises/stretches that rotate your abdominal area.
  • Be mindful of how stress might be affecting your bowel.
  • Reduce your caffeine and alcohol intake.

If these suggestions have minimal effect:

  • Speak with your dietitian about the potential benefits of a probiotic and/or a possible underlying food intolerance.
  • Liaise with your GP about the potential side effects of any medication you may be taking and maybe discuss the need for a gastroenterology referral.


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