Diarrhoea, Malabsorption & Abdominal Pain
Use time course, alarm features and hydration status to distinguish self-limited illness from inflammatory or surgical disease.
Quick revision ↓ Medical Dictionary
01Assess severity and hydration
Ask about duration, stool frequency, blood, fever, travel, antibiotics, food exposure and sick contacts. Examine hydration, urine output, perfusion and abdominal findings. Severe pain, guarding, shock or marked distension needs urgent assessment for a surgical or toxic process. Older and immunocompromised patients can deteriorate with less obvious symptoms. Oral rehydration is useful when safe and tolerated, while significant compromise may require monitored intravenous replacement.
02Target infectious testing
Most brief uncomplicated watery diarrhoea does not require broad investigations, but bloody stools, systemic illness, immunosuppression, outbreaks or persistent symptoms may justify specific stool tests. Recent antibiotic exposure raises concern for Clostridioides difficile. Infection-control measures depend on the suspected pathogen. Antibiotics are not automatically helpful in every diarrhoeal illness and can sometimes cause harm; use a cause-specific local pathway.
03Recognise inflammatory disease
Persistent bloody diarrhoea, urgency, weight loss and extraintestinal symptoms can suggest inflammatory bowel disease, but infection must be considered. Assess severity, anaemia, inflammatory markers and nutritional status. Faecal calprotectin supports assessment of intestinal inflammation in selected situations but is not specific for one diagnosis. Severe colitis with systemic toxicity or distension requires urgent specialist review rather than escalating antimotility treatment.
04Investigate malabsorption
Chronic diarrhoea with weight loss, nutrient deficiency or bulky stools suggests malabsorption among other causes. Coeliac testing commonly starts with appropriate serology and total IgA while the person is eating gluten; prior gluten exclusion can reduce test sensitivity. Pancreatic and other intestinal causes need targeted evaluation. Avoid declaring a functional disorder before considering alarm features and clinically indicated investigations.
05Review recurrent symptoms
Functional bowel disorders are diagnosed positively from a compatible pattern after appropriate assessment, not simply because a single test is normal. Discuss diet, medicines and psychosocial factors without implying symptoms are imaginary. New bleeding, progressive weight loss, nocturnal symptoms or a significant change in pattern warrants renewed review. A shared plan should specify symptom management, follow-up and reasons for earlier reassessment.
High-Yield Revision
- Hydration and abdominal red flags determine urgency.
- Test for coeliac disease while gluten is still being consumed when feasible.
- Persistent alarm features require reassessment despite an earlier benign label.
Common Pitfalls
- Do not prescribe antibiotics automatically for every diarrhoeal illness.
- Avoid antimotility treatment in suspected severe inflammatory or toxic colitis without specialist advice.
References & Further Reading
Read the relevant guideline sections alongside these original clinical teaching cases. Local pathways, available services and individual patient factors determine care.
Reference review: 27 September 2026. Consult current local protocols for prescribing, procedures and escalation.