Why are IBS symptoms worse in morning?

Updated July 19, 2017

Irritable bowel syndrome, or IBS, is a disorder that affects the bowels, causing symptoms like diarrhoea or constipation. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), about 20 per cent of the adult population in the United States has symptoms of irritable bowel syndrome.


Abdominal pain, discomfort and bloating are common in irritable bowel syndrome. Symptoms may vary among patients; some people have constipation, some have diarrhoea, and some alternate between the two.


Although research has not yielded any specific cause for irritable bowel syndrome, some researchers theorise IBS patients have a particularly sensitive colon that is reactive to stress and certain foods. Other issues, like immune system problems, coeliac disease and bacterial infection, may play a role in irritable bowel syndrome.

Morning Symptoms

Diarrhoea often occurs when the patient wakes up in the morning or after a meal. Mucus is frequently present in the stool.

Food Allergy

Food intolerances are fairly common in IBS patients, so some doctors believe food allergies or sensitivities may contribute to irritable bowel syndrome. These sensitivities may also be responsible for problems with diarrhoea in the morning or after meals.


According to the University of North Carolina's Center for Functional GI and Motility Disorders, researchers in Italy have reported that the natural pattern of cortisol levels--cortisol is higher in the morning and lower in the evening--in IBS patients is exaggerated. This indicates higher cortisol levels may contribute to worse symptoms of irritable bowel syndrome in the morning.

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About the Author

Jules Stark has been a writer for most of her adult life. Her creative work has been featured in college literary magazines, and her non-fiction articles can be found on She graduated from a small liberal arts college with a Bachelor of Arts in art and archaeology, minoring in both classics and U.S. history.