When can yellow stool suggest poor fat absorption?
Diet or diarrhoea can change stool colour without serious illness. Recurrent yellow, greasy, bulky, foul-smelling stool with weight loss may suggest impaired fat absorption. Colour alone cannot diagnose pancreatic or liver disease.
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Texture matters as well as colour
Record duration, visible oil, difficulty cleaning stool, weight changes, diet and medicines. Stool or blood tests are selected according to the pattern; not everyone requires extensive imaging or pancreatic enzymes.
Yellow differs from pale clay-coloured stool
Very pale or clay-coloured stool with yellow eyes and dark urine needs prompt assessment for impaired bile flow. Fever or severe upper abdominal pain makes urgent review particularly important.
Avoid treating an assumed cause
If coeliac disease is suspected, discuss testing before starting a gluten-free diet because restriction may alter results. Do not replace assessment of persistent symptoms and weight loss with digestive-enzyme supplements.
Related reading: Does green stool indicate illness, or can food cause it?.