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Gastrointestinal (GI) disturbance

You may experience constipation, diarrhoea or a combination of the two across your menstrual cycle.

What phase of your menstrual cycle do you experience GI disturbance?

Changes in GI usually occur in the luteal phase and start of a period due to the rise and fall of progesterone.

Mid Luteal Phase

Causes of GI disturbance

Several reasons have been hypothesised for these symptoms:

Progesterone has been linked with slowing down our “gut motility”. This is the speed that digested food moves through the GI tract. When progesterone is high, there may be slower GI motility causing constipation. 

When progesterone drops at the start of a period, prostaglandins can cause smooth muscle contractions, as well as changes to fluid and electrolyte balance in the small bowel, all of which can cause diarrhoea (with potential constipation depending on hydration levels).

Some limited evidence has shown that GI disturbance is increased in individuals who also experience mood changes and fatigue in the late luteal phase.

How to manage GI disturbance

Monitor your fluid intake – check that you are drinking enough if you experience symptoms of increased sweating, diarrhea or vomiting. Urine colour is a good indicator of hydration levels – download a urine colour chart from the NHS. 

If you are losing more fluid than normal then you may want to consider an electrolyte in your drinks. You can make your own by adding a pinch of salt and fruit juice to your water (50:50 juice:water)

Caffeine can cause changes to your bowel habits so you may want to swap your tea/coffee for an alternative: ginger tea may help with nausea and peppermint tea may help with stomach cramps. 

Avoid any food or drinks that contain sweeteners ending in “-ol” as these can have a laxative effect. These type of sweeteners are commonly found in chewing gum and “sugar free” products.

Probiotics can improve gut health which may support with reducing these types of symptoms. Yakult, Actimel or Activia yogurts consumed twice a day can provide a source of probiotic. 

Prebiotics are also needed for probiotics to be effective, found in: beetroot, garlic, leeks, chickpeas, lentils, baked beans, apricots, nectarines, watermelon, mango, nuts, chamomile tea. These would also be useful after these symptoms have passed as they will help to restore your gut bacteria to normal levels.

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