Colonoscopy and Breastfeeding Mothers

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The information provided is taken from various reference sources.  It is provided as a guideline.  No responsibility can be taken by the author or the Breastfeeding Network for the way in which the information is used.  Clinical decisions remain the responsibility of medical and breastfeeding practitioners.  The data presented here is intended to provide some immediate information but cannot replace input from professionals.

Colonoscopy is carried out under light sedation in order to examine the inside of the colon. A small flexible tube is passed in through the anus and into the intestine. It may be used to diagnose or exclude conditions such as inflammatory bowel disease or diverticulitis. The examination takes under half an hour and in most cases the patient is not asleep but drowsy and relaxed. For further information see

The colonoscopy procedure is uncomfortable but not painful and is over in a short period. In many instances the preparation period is worse as the urgency to pass motions can be extreme. If a breastfeeding mother needs to have this procedure it may be important that someone is with her to look after the baby during the bowel preparation period, as well as on the day following. She may be drowsy afterwards from lack of food in addition to the colonoscopy and sedation.

In order that the medical staff can examine the gut thoroughly, bowel cleansing is necessary to clear out all faeces in advance of the procedure. This requires a low residue diet for one or two days and the use of a strong laxative the day before the procedure to produce liquid motions as the gut is cleared.

The laxative normally used is a stimulant laxative such as sodium picosulphate (Picolax ®) which is not known to be absorbed into breastmilk or the osmotic laxative macrogol 3350 (Klean Prep ®). Macrogol is an inert substance that passes through the gut without being absorbed into the body. It works because it causes water to be retained in the bowel instead of being absorbed into the body. Enemas such as Fleet ® may also be used without affecting the breastfed baby.

Care should be taken to ensure that the mother remains adequately hydrated throughout the preparation period and on the day of the procedure by drinking plenty of water as permitted by the pre-operative instructions.

Short acting hypnotics such as midazolam, fentanyl and pethidine are used during the procedure itself to sedate the patient and are not contra- indicated during breastfeeding unless the baby is at risk of respiratory depression.

Midazolam : The small amounts of midazolam excreted into breastmilk would not be expected to cause adverse effects in most breastfed infants. New guidelines from the Assoc of Anaesthetists Aug 2020 that no delay is necessary in any age group

See also 2012 ASGE  Guideline

Fentanyl : No waiting period or discarding of milk is required before resuming breastfeeding after fentanyl is used for short procedures (e.g., for endoscopy) [Lactmed]

Pethidine: A  single dose for anesthesia or conscious sedation usually does not cause problems in older breastfed infants. [Lactmed]

Drugs used in this procedure are not licensed for use during breastfeeding and are therefore not recommended for use by the manufacturers. This does not imply that they are unsafe.

See information sheet on patient information leaflets on the website for further explanation


  • British National Formulary
  • Hale T. W Medications in Mothers Milk 2016 (17th Ed) Hale publishing
  • Jones W Breastfeeding and Medication 2013 Routledge
  • Lactmed website
  • Mitchell J, Jones W, Winkley E, Kinsella. S.M Guideline on anaesthesia and sedation in breastfeeding women 2020. Guideline from the Association of Anaesthetists. First published: 01 August 2020
  • Shergill AK, Ben-Menachem T, Chandrasekhara V, et al. Guidelines for endoscopy in pregnant and lactating women GASTROINTESTINAL ENDOSCOPY 2012;76 (1): 18-24)

©Dr Wendy Jones MBE, MRPharmS and the Breastfeeding Network August 2020