When to worry about diarrhoea with irritable bowel syndrome

Irritable bowel syndrome can cause diarrhoea, abdominal pain, bloating and an urgent need to use the toilet. Symptoms often fluctuate and may relate to meals, stress or changes in routine. A sudden change, steadily worsening diarrhoea, or symptoms that wake you from sleep is different from a familiar flare and should be assessed rather than assumed to be IBS.

Drink regularly and choose foods that have previously been gentle on your digestion. Keep a brief diary of meals, bowel changes, pain and possible triggers. Avoid making broad food exclusions without guidance, because a restricted diet can make balanced nutrition difficult. Use only treatments already recommended for your IBS.

Seek urgent help for blood or black stool, severe or localised pain, faintness, confusion, inability to drink or signs of dehydration. Arrange a clinical review for unexplained weight loss, fever, persistent night-time diarrhoea, anaemia symptoms, repeated vomiting, or a bowel pattern that no longer resembles your usual IBS.

Ask whether your symptoms fit IBS, whether tests are needed for other bowel conditions, and which dietary or symptom treatments are suitable. Describe your normal pattern, the recent change, stool appearance, family history and any medicines or supplements.