Diarrhoea

Category: Digestive & Abdomen · All digestive symptoms

What it can feel like

Diarrhoea means loose or watery stools passed more often than usual. Most episodes are caused by infection, last a few days, and the main danger is dehydration. Diarrhoea lasting more than four weeks, or recurring, needs a different kind of investigation.

Possible causes

A symptom can have many causes, and most are not serious. The lists below group conditions this symptom can be associated with — common causes first. They are possibilities to discuss with a clinician, not a diagnosis.

Common causes

Diarrhoea can be associated with viral and bacterial gut infections, food poisoning, travel, anxiety, caffeine and alcohol, artificial sweeteners, and medicines — antibiotics and metformin are common culprits.

Other possible causes

Persistent diarrhoea can be associated with inflammatory bowel disease, coeliac disease, irritable bowel patterns, bile-acid diarrhoea after gallbladder removal, an overactive thyroid, and occasionally bowel cancer.

Red flags — when to seek help promptly

Diarrhoea with blood or black stools
Diarrhoea with signs of dehydration — dizziness, very little urine, dry mouth
Diarrhoea lasting more than four weeks, or waking you from sleep at night
Diarrhoea with unexplained weight loss or persistent fever
Diarrhoea in a baby, or in someone frail, elderly or with a weakened immune system

What a clinician may do

A clinician will ask about duration, blood, travel, contacts, food and medicines. Stool samples can be tested for infection and inflammation; blood tests and bowel investigations (including a stool test for hidden blood and colonoscopy) follow for persistent cases.

Watch: related videos

Examination and clinical videos from the MedicalVideos.com library relevant to this symptom. Some clinical footage is graphic — that is the nature of a medical video library.

▶ WatchDiarrhea in childrenWatch on MedicalVideos.com ▶ WatchVomiting and diarrhea in kidsWatch on MedicalVideos.com ▶ WatchUsmle step 2 cs diarrheaWatch on MedicalVideos.com

Related guides on MedicalVideos.com

Frequently asked questions

What should I drink when I have diarrhoea?

Small, frequent drinks of water or oral rehydration solution — the salts matter as much as the water. Avoid very sugary drinks, which can worsen diarrhoea. Children and older people dehydrate faster and should be watched closely.

Why does it matter if diarrhoea wakes me at night?

Functional bowel patterns such as irritable bowel syndrome typically quieten during sleep. Diarrhoea that regularly wakes you suggests inflammation or another organic cause and should be investigated rather than managed as irritable bowel.

Related symptoms — Digestive & Abdomen

Abdominal pain Black stools Bloating Blood in the stool Change in bowel habit Constipation

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Please note: This page is educational information about a symptom. A symptom alone cannot diagnose any condition, and the causes listed here are possibilities, not a diagnosis. If you are worried about a symptom — especially one that is new, severe, getting worse or not going away — please see your own clinician, who can examine you and arrange tests. In an emergency, call your local emergency number.