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IM16.1-17 | Diarrheal Disorders — Assignment

CLINICAL SCENARIO

This assignment asks you to write a structured clinical case report for a patient presenting with diarrhoea. You may base this on a real patient you have clerked during your clinical posting, or on the constructed case scenario provided in Section A below. Your report must demonstrate systematic history-taking, clinical examination, mechanism-based differential diagnosis generation, appropriate investigation planning and interpretation, and an evidence-based management plan. All clinical reasoning must be explicitly stated — do not simply list findings.

Constructed case scenario (if no real patient available): A 35-year-old farmer from rural Tamil Nadu presents to a district hospital OPD with a 5-day history of watery diarrhoea (8-10 times/day), two vomiting episodes, and progressive weakness. He reports consuming well water from a shared source. No blood in stool. He appears ill: skin pinch retracts in 2 seconds, dry oral mucosa, sunken eyes. Temperature 37.2°C, pulse 102/min, BP 98/64 mmHg. He mentions one of his neighbours has similar symptoms.

Instructions

Write a structured clinical case report in the six sections below. Use clear clinical language. For every investigation you order, state what you expect to find and what you will do with the result. For every drug, state the dose, route, and duration. Do not reproduce SDL text verbatim — integrate and apply your own clinical reasoning. Word limit: 1,100-1,400 words total across all sections.

Length: 1,100-1,400 words across all sections

What to Submit

Section 1: Clinical History

Guidance: Document the history systematically across all required domains. For stool characterisation, address: frequency, volume per episode, consistency (watery/semi-formed/formed), colour, presence or absence of blood and mucus, odour, and any temporal pattern (postprandial, nocturnal). Address dietary history (specific foods consumed in the 6-72 hours before onset), water source (piped, well, treated), travel (recent), sexual history (if relevant), concomitant illnesses (HIV, diabetes, IBD history), and medications (antibiotics, antacids, laxatives). Classify the diarrhoea by duration (acute <2 weeks, persistent 2-4 weeks, chronic >4 weeks) and clearly state whether the presentation is diarrhoea or dysentery. Identify and list any red flag features. Approximately 250 words.

Section 2: Physical Examination

Guidance: Describe the general examination systematically. For dehydration: document the specific signs you would assess (mental state, sunken eyes, presence of tears, mouth dryness, skin pinch recoil time, radial pulse, respiratory rate) and apply them to grade dehydration as no/some/severe dehydration (WHO criteria). For the abdominal examination: describe inspection (distension, visible peristalsis), auscultation (bowel sounds — increased/decreased/tinkling), palpation (tenderness location, guarding, organomegaly, mass), and percussion findings. Note any perianal findings. State how the examination findings contribute to localising the disease (small bowel vs large bowel pattern) and assessing systemic severity. Approximately 200 words.

Section 3: Differential Diagnosis

Guidance: List at least three differential diagnoses in order of probability. For each, state: (a) the pathophysiological mechanism (secretory/osmotic/inflammatory/malabsorptive), (b) the key clinical features from this case that support it, and (c) one feature that argues against it. Prioritise your most likely diagnosis and explain your reasoning. For an Indian clinical context, consider common pathogens (cholera, amoebiasis, giardiasis, Salmonella, Shigella, Cryptosporidium) and non-infectious causes (IBD, IBS, coeliac, malabsorption syndromes) as appropriate to the case chronology. Approximately 200 words.

Section 4: Investigation Plan and Interpretation

Guidance: State your investigation plan in order of priority. Specify for each investigation: what it tests, what result you expect, and how it will change management. Include: (a) first-line investigations (CBC, stool examination — wet mount, pus cells, RBC, fat globules; occult blood if indicated); (b) stool culture indications — state precisely when culture is warranted in this case and the expected organism; (c) blood investigations (electrolytes, renal function, albumin if chronic); and (d) advanced investigations (colonoscopy with biopsy, antibody panel, imaging) if the case has chronic components. Describe the microscopic morphology of at least one stool parasite that might be found (if relevant), referring to the examination technique. Approximately 250 words.

Section 5: Management Plan

Guidance: Write a structured management plan addressing three domains: (1) Rehydration — state the WHO ORS composition (Na 75, glucose 75, K 20, Cl 65, citrate 10 mmol/L; total 245 mOsm/L) and apply the appropriate WHO Plan (A/B/C) based on your dehydration grading, with the volume and route; (2) Pharmacotherapy — select the appropriate antibiotic or antiparasitic with drug name, dose, route, and duration, citing the indication; if no antibiotic is indicated, state why; explicitly address whether loperamide or other antimotility agents are indicated or contraindicated in this case and why; (3) Monitoring and follow-up — state the clinical parameters to monitor, when to escalate, and diet advice. If the case has a chronic/IBD component, address the pharmacological step-up ladder and surgery indications briefly. Approximately 250 words.

Section 6: Reflection

Guidance: Write a brief personal reflection on what this case taught you that you could not have learned from a textbook alone. Focus on one specific clinical reasoning moment — for example, how a single history feature (e.g., stool stopping with fasting) changed your entire differential, or how the examination finding of absent bowel sounds in diarrhoea signalled a complication. Connect this to a competency you feel you have improved. Approximately 100-150 words.

Grading Rubric — Diarrhoeal Disorders Clinical Case Report Rubric

Criterion	Points	Full-marks descriptor
Clinical History (Section 1): Covers all relevant domains — stool characterisation, dietary and water source history, travel, sexual history, concomitant illnesses, and medications. Identifies red flags and uses history to differentiate acute/persistent/chronic and diarrhoea/dysentery.	20 pts	All six history domains covered; stool characterised by frequency, volume, consistency, colour, blood/mucus, and smell; epidemiological, dietary, travel, sexual, and drug history all addressed; red flags explicitly identified; duration correctly classified.
Physical Examination (Section 2): Systematic description of general examination (dehydration assessment using WHO criteria), abdominal examination findings, and their interpretation to estimate dehydration severity and localise disease.	15 pts	WHO dehydration signs listed accurately and graded (Plan A/B/C criteria); abdominal examination systematically described (tenderness site, bowel sounds, organomegaly, PR if applicable); examination findings linked to differential diagnosis.
Differential Diagnosis and Prioritisation (Section 3): Generates a differential diagnosis from the history and examination, correctly applies the mechanism-based framework (secretory/osmotic/inflammatory/malabsorptive), and prioritises the most likely diagnosis with reasoning.	20 pts	Correctly identifies at least three differential diagnoses; assigns each to the appropriate mechanism; uses clinical features to prioritise the most likely; Indian-context pathogens (cholera, amoebiasis, giardiasis, Shigella, Salmonella) considered where relevant.
Investigation Plan and Interpretation (Section 4): Selects appropriate first-line (CBC, stool examination) and second-line investigations; correctly interprets stool microscopy morphology (parasites, pus cells, RBCs); applies indications for stool/blood culture and colonoscopy correctly.	20 pts	Correct first-line investigations (CBC + stool exam) with indications stated; stool microscopy findings interpreted correctly (at least one parasite described by morphology); specific stool/blood culture indications applied; advanced investigations (colonoscopy, antibodies, imaging) selected appropriately for chronic case components.
Management Plan (Section 5): Addresses rehydration (correct WHO plan applied to dehydration grade), antibiotic/antiparasitic use (correct drug, dose, duration, and indication), and discusses contraindication of antimotility agents in dysentery.	20 pts	WHO ORS composition cited (Na 75, glucose 75, 245 mOsm/L); correct Plan A/B/C applied to graded dehydration; antibiotic or antiparasitic chosen correctly with dose and duration (e.g., metronidazole for amoebiasis; doxycycline for cholera; mesalazine/steroids for IBD with correct escalation); loperamide contraindication in dysentery explicitly stated.
Reflection and Learning (Section 6): Reflects on the difference between acute self-limiting diarrhoea and chronic diarrhoea requiring structured investigation; identifies one specific clinical learning point from the case that extends beyond textbook knowledge.	5 pts	Reflection is specific, personal, and identifies a concrete learning point (e.g., how a stool osmotic gap guided the mechanism diagnosis, or why loperamide could be harmful in a patient initially mistaken for simple gastroenteritis).

PEER REVIEW

Review your peer's case report using the rubric criteria. For each section, assign a score and write one specific comment that explains your assessment — do not copy the rubric descriptor. For Section 1 (History), verify that stool characterisation includes blood/mucus (diarrhoea vs dysentery distinction). For Section 4 (Investigations), check whether the stool microscopy section describes parasite morphology specifically (not just 'stool for ova and cysts'). For Section 5 (Management), verify that WHO ORS composition is cited and the correct Plan is applied to the dehydration grade described in Section 2. If loperamide is recommended for a patient with bloody stools, record this as a critical error in your review. Complete your review within 72 hours.