Does irritable bowel syndrome cause diarrhoea?

Irritable bowel syndrome can change the speed and sensitivity of digestion. Stools may become loose or urgent, and symptoms may follow meals, stress, or a familiar flare pattern. Some people have diarrhoea most of the time, while others alternate between loose stools and constipation. Diarrhoea can also result from infection, food intolerance, medicines, inflammatory bowel disease, or other conditions. A clinician considers how long it has lasted, whether it wakes you, the presence of pain, and any blood, fever, or weight change before attributing it to irritable bowel syndrome.

Record stool changes, urgency, meals, travel, medicines, and accompanying pain. Drink fluids regularly, particularly during loose-stool episodes, and choose simple foods that you tolerate. Limit foods or drinks that clearly trigger symptoms without cutting out many foods at once. Wash hands carefully if an infection is possible. A clinician can discuss suitable medicines for urgency or diarrhoea after considering the cause; do not use anti-diarrhoeal treatment to mask severe symptoms or bleeding.

Arrange a medical review if diarrhoea persists, repeatedly returns, disrupts sleep or work, or causes signs of dehydration such as very dark urine, marked thirst, or faintness. Seek urgent care for blood or black stools, severe abdominal pain, repeated vomiting, high fever, confusion, or inability to keep fluids down. These features require assessment for causes other than irritable bowel syndrome.

Ask whether your bowel pattern needs tests, how to manage urgency safely, whether any medicine or food may be contributing, how to replace fluids, and which symptoms should lead you to seek urgent help.