Can you prepare a PDF case study on chronic dysentery in a 32‑year‑old male, including relevant laboratory reports and clinical photographs?

Chronic Dysentery Case Study: 32-Year-Old Male

Clinical Presentation and Initial Assessment

Chronic dysentery in a 32-year-old male requires immediate systematic evaluation to differentiate infectious, inflammatory, and parasitic etiologies, with particular attention to Shigella, Salmonella, Campylobacter, and Entamoeba histolytica as the most common bacterial and parasitic causes worldwide. 1

Key Historical Features to Document

• Duration and pattern of bloody diarrhea: Chronic dysentery is defined as bloody diarrhea persisting beyond 14 days, distinguishing it from acute presentations 2, 1
• Travel history: Recent travel to endemic regions (South Asia, sub-Saharan Africa, Central/South America) significantly increases probability of Entamoeba histolytica, Shigella, and other tropical pathogens 2, 1
• Antibiotic exposure: Recent antibiotic use within 8-12 weeks raises suspicion for Clostridium difficile infection 2
• Immunosuppression status: HIV/AIDS, chemotherapy, or steroid use predisposes to opportunistic infections including Cryptosporidium, Cystoisospora, microsporidia, and Cytomegalovirus 2
• Associated symptoms: Fever, abdominal pain, weight loss, and nocturnal diarrhea are alarm features requiring urgent investigation 2, 3

Critical Alarm Features Requiring Urgent Evaluation

• Unintentional weight loss (excludes functional disorders) 3, 4
• Nocturnal diarrhea (suggests organic disease) 2, 4
• Visible blood in stool with anemia 3, 4
• Fever persisting beyond 48 hours 2, 1
• Recent onset (<3 months) in patient >45 years 3

Mandatory First-Line Laboratory Investigations

Blood Testing Panel

The British Society of Gastroenterology mandates a comprehensive baseline blood panel for all patients with chronic diarrhea to identify anemia, inflammation, malabsorption, and endocrine causes. 3

• Complete blood count (CBC): Detects anemia signaling inflammatory bowel disease, celiac disease, or malignancy 3, 5
• C-reactive protein (CRP) and ESR: Elevated levels differentiate inflammatory from functional diarrhea with high specificity for organic disease 3, 5
• Comprehensive metabolic panel: Low albumin has high specificity (>90%) for organic causes of chronic diarrhea 2, 3
• Liver function tests: Screen for hepatobiliary etiologies 3, 5
• Iron studies, vitamin B12, folate: Identify malabsorption common in celiac disease and inflammatory bowel disease 3, 5
• Thyroid-stimulating hormone (TSH): Hyperthyroidism is a frequent endocrine cause 2, 3
• Celiac serology: IgA tissue transglutaminase (tTG) with total IgA is mandatory (prevalence 1:200-1:559 in Western populations); total IgA must be measured because selective IgA deficiency occurs in ~2.6% of celiac patients versus 0.2% in general population, producing false-negative results 2, 3, 5

Stool Studies

• Fecal calprotectin: Values >50 mg/g have >90% sensitivity for inflammatory bowel disease; mandatory in patients <40 years 2, 3, 5
• Stool culture and ova/parasites: Three fresh stool specimens collected on consecutive days to identify Shigella, Salmonella, Campylobacter, and Entamoeba histolytica 1, 6
• Giardia antigen testing: Strongly recommended due to high prevalence and excellent diagnostic accuracy 4, 5
• Clostridium difficile toxin: If antibiotic exposure within 8-12 weeks 2
• Fecal immunochemical test (FIT): Screens for occult blood loss and prioritizes colonoscopy urgency 2, 3

Endoscopic Evaluation Strategy

Colonoscopy with biopsies of right and left colon (not rectal) is mandatory in this 32-year-old patient because chronic dysentery with visible blood constitutes an alarm feature requiring urgent investigation within 2-4 weeks. 2, 3

Biopsy Protocol

• Obtain biopsies from right and left colon even if mucosa appears normal, as microscopic colitis presents with normal endoscopic appearance but characteristic histologic changes 2, 3
• Rectal biopsies are not required for microscopic colitis diagnosis 2, 3

Indications for Upper Endoscopy

• Positive celiac serology requiring duodenal biopsies for confirmation 3
• Clinical suspicion of small bowel enteropathy despite negative serology 3

Pathogen-Specific Considerations in Chronic Dysentery

Bacterial Etiologies

Shigella, Salmonella, and Campylobacter remain the most frequent bacterial causes of dysentery worldwide, with Shigella accounting for 30% and Salmonella 25% of hospitalized dysentery cases. 1, 6

• Shigella species: Most common bacterial cause; clinical and laboratory parameters cannot reliably differentiate Shigella from other bacterial pathogens, necessitating stool culture 6
• Salmonella species: Second most common; may present with prolonged symptoms requiring antibiotic therapy 1, 6
• Campylobacter jejuni: Less common (2% of cases) but important differential 6
• Shiga toxin-producing E. coli (STEC): Important in industrialized countries; patients typically afebrile at presentation with severe abdominal pain and grossly bloody stools 2, 1

Parasitic Etiologies

• Entamoeba histolytica: Must be considered in developing world, particularly rural/periurban areas; presents with fever and amoebic dysentery requiring specific antiparasitic therapy 2, 1
• Schistosoma mansoni: In early infection causes acute schistosomiasis (Katayama syndrome); chronic infection results in hepatosplenomegaly and portal hypertension 2
• Giardia lamblia: Causes persistent diarrhea; high diagnostic yield with antigen testing 2, 4

Helminthic Infections

• Strongyloides stercoralis: Presents with larva currens, gastrointestinal symptoms, and eosinophilia; hyperinfestation syndrome occurs in immunosuppressed patients with defective granulocyte function (chemotherapy, steroids, HTLV-1 infection) 2
• Schistosoma species: Chronic infection causes abdominal pain, diarrhea, or dysentery in heavy acute infections 2

Advanced (Third-Line) Testing for Persistent Cases

These investigations are reserved only for cases where initial blood tests, stool studies, and colonoscopy fail to establish a diagnosis. 2, 3

• Bile acid diarrhea testing: SeHCAT scan or serum 7α-hydroxy-4-cholesten-3-one; empiric trials of cholestyramine are discouraged without positive diagnosis 2, 3, 4
• Hydrogen breath testing: For lactose maldigestion; empiric lactose-withdrawal trial is acceptable alternative 2, 3
• Fecal elastase: Assess pancreatic exocrine insufficiency when fat malabsorption suspected (bulky, pale, malodorous stools) 2, 3
• MR enterography or video capsule endoscopy: Evaluate small bowel pathology when all other investigations unrevealing 2, 3

Treatment Considerations Based on Etiology

Bacterial Dysentery

Empiric antibiotic treatment is justified in hospitalized patients with clinical dysentery, as 40% of hospitalized cases have bacterial pathogens requiring specific therapy. 6

• Antibiotic selection should be guided by local resistance patterns and culture sensitivities 2, 1
• Specific indications for antimicrobials include confirmed Shigella, Salmonella, Campylobacter, and amoebic dysentery 2, 1
• Anti-diarrheal agents are contraindicated in acute dysentery 2

Parasitic Dysentery

• Entamoeba histolytica: Requires specific antiparasitic therapy 2, 1
• Giardiasis: Treat acute giardiasis with appropriate antiparasitic agents 2
• Strongyloidiasis: Albendazole 400 mg single dose or ivermectin; hyperinfestation requires aggressive treatment 2

Inflammatory Bowel Disease

• If colonoscopy with biopsies confirms inflammatory bowel disease, refer to gastroenterology for disease-specific therapy 2, 7

Critical Pitfalls to Avoid

• Premature IBS diagnosis: Rome criteria have specificity of only 52-74%, missing 26-48% of organic diseases including microscopic colitis, inflammatory bowel disease, and bile acid diarrhea; functional diagnosis requires completed negative workup 3
• Relying solely on ESR/CRP: Fecal calprotectin and lactoferrin are more sensitive markers for inflammatory bowel disease 5
• Failing to check total IgA: When testing for celiac disease, omitting total IgA leads to false-negative results in IgA-deficient patients 3, 5
• Single stool specimen: Three consecutive daily specimens increase diagnostic yield for parasites 1, 6
• Delaying colonoscopy: Visible blood in stool is an absolute indication for colonoscopy within 2-4 weeks regardless of age 3, 4

Sample Laboratory Report Format

Complete Blood Count

• Hemoglobin: [value] g/dL (reference: 13.5-17.5)
• MCV: [value] fL (reference: 80-100)
• White blood cell count: [value] × 10⁹/L (reference: 4.5-11.0)
• Platelet count: [value] × 10⁹/L (reference: 150-400)

Inflammatory Markers

• C-reactive protein: [value] mg/L (reference: <5)
• Erythrocyte sedimentation rate: [value] mm/hr (reference: <20)

Metabolic Panel

• Albumin: [value] g/dL (reference: 3.5-5.0)
• Electrolytes, renal function, liver enzymes

Celiac Serology

• IgA tissue transglutaminase: [value] U/mL (reference: <4)
• Total IgA: [value] mg/dL (reference: 70-400)

Stool Studies

• Fecal calprotectin: [value] mg/g (reference: <50)
• Stool culture: [organism identified or negative]
• Ova and parasites: [organism identified or negative]
• Giardia antigen: [positive/negative]
• Clostridium difficile toxin: [positive/negative]

Endoscopy Report

• Colonoscopy findings: [description of mucosal appearance]
• Biopsy locations: Right colon, left colon
• Histopathology: [microscopic findings]