IM16.{4-5,7} | Diarrheal Disorder Clinical Evaluation — Summary & Reflection

KEY TAKEAWAYS

History domains: Onset/duration (acute/persistent/chronic), stool characterisation (frequency, volume, colour, blood/mucus), associated symptoms (fever, pain, tenesmus, vomiting), dietary history (foods 6–72 hrs before onset, shared meals, festival/mass gatherings), travel (pilgrimages, rural/international), sexual history (MSM → Shigella/LGV/gonorrhoea; HIV status → Cryptosporidium/CMV/Microsporidia), occupational/medication history (antibiotics → C. diff; metformin), and systemic review (thyroid, DM, IBD extra-intestinal features, family history of CRC/IBD/coeliac).

Physical examination: General assessment (consciousness, nutrition, pallor/jaundice), vital signs (HR, BP lying + standing for orthostasis, temperature, RR), dehydration signs (sunken eyes, dry mucosa, skin turgor ≥2 sec = severe), abdominal examination (inspection/auscultation/palpation/percussion — tenderness site directs differential), perianal inspection and DRE (fistulae/tags = Crohn's, hard mass = CRC), and targeted extraintestinal examination (joints, eyes, skin for IBD; rose spots/splenomegaly for enteric fever; hepatomegaly/intercostal tenderness for amoebic liver abscess).

Differential generation (prioritised): Duration → mechanism (watery vs bloody) → risk factors → systemic clues → must-not-miss filter. Must-not-miss: colorectal carcinoma (age >50 + rectal bleeding + weight loss + family history), HUS (bloody diarrhoea + anaemia + thrombocytopaenia + AKI in child), toxic megacolon (severe UC + colonic dilatation), amoebic liver abscess, enteric fever with perforation risk at week 3.

Documentation: SOAP format; quantify findings; present mechanism-first narrative; differential tiered: most likely → alternative → must-not-miss.

REFLECT

Think about the last time you observed a history-taking session in a general medicine ward or emergency department. How many of the seven history domains described in this module were covered? Was the sexual history taken at all? Was the dietary history specific enough to suggest a food source? Was the duration documented in a way that classified the presentation as acute, persistent, or chronic — or was it just written as 'loose stools for a few weeks'? Clinical documentation that omits these domains is not just incomplete for the examiner — it means a subsequent treating clinician may miss a crucial diagnosis. As you move into clinical postings, practise eliciting the full diarrhoeal history systematically on every patient, even when the presentation seems straightforward. The skill becomes automatic only through repetition, and the one time it is not done is often the one time it matters most.