Acute enteritis is a sudden inflammatory or infectious insult to the small-intestinal mucosa. It peaks within hours to a few days, usually resolves within one week, and ranges from mild cramps to rapidly dehydrating diarrhea. Recognising the characteristic features helps guide fluid replacement, diet choices, and the decision to seek medical care. Red-flag combinations demanding urgent reviewPersistent vomiting preventing oral intake, bloody diarrhea with orthostatic hypotension, continuous abdominal rigidity or localized rebound tenderness, fever >39 °C with altered consciousness, and oliguria despite attempted rehydration. Core intestinal symptomsDiarrhea: watery or loose, occasionally rice-water or blood-flecked; defined as ≥3 stools per day... Learn more