Chronic_Diarrhoea_53_Slides_Full presentation.pptx

Chronic Diarrhea in Adults — Overview
Chronic diarrhea is defined as the passage of loose or watery stools lasting more than 4 weeks. It can result from various gastrointestinal, endocrine, infectious, or medication-related causes.


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1. Definition

Chronic diarrhea: ≥3 loose or watery stools per day for >4 weeks.

Acute diarrhea: 100 mOsm/kg) Lactose intolerance, sorbitol ingestion
Secretory diarrhea Increased secretion or decreased absorption of electrolytes Persists with fasting; low osmotic gap (50 years or alarm features)

Upper GI endoscopy with duodenal biopsy (if celiac suspected)

Hydrogen breath test (for lactose intolerance or SIBO)

Imaging: CT/MRI enterography if IBD or pancreatic disease suspected.



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5. Management (Cause-Directed)

Cause Treatment

Celiac disease Gluten-free diet
Lactose intolerance Lactose restriction, lactase enzyme
IBD Anti-inflammatory or immunosupp

1. Chronic Diarrhoea in Adults: · A systematic approach to evaluation, diagnosis, and management. Chronic Diarrhoea in Adults | Dr. Nasser 1

2. Definition of Chronic Diarrhoea · Presence of ≥3 loose stools per day for more than 4 weeks. · Stool weight >200 g/day (research use). · Increased stool weight with normal consistency may not indicate diarrhoea. Chronic Diarrhoea in Adults | Dr. Nasser 2

3. Diagnostic Challenge · Many aetiologies present similarly. · Causes range from benign to life-threatening. · Systematic evaluation and local epidemiology awareness are key. Chronic Diarrhoea in Adults | Dr. Nasser 3

4. Anatomical Classification · Colonic · Small Bowel · Pancreatic · Functional · Endocrine · Systemic · Miscellaneous Chronic Diarrhoea in Adults | Dr. Nasser 4

5. Colonic Causes · IBD (UC, Crohn’s) · Microscopic Colitis · Infective Gastroenteritis · Ischaemic Colitis · Malignancy · GVHD Chronic Diarrhoea in Adults | Dr. Nasser 5

6. Small Bowel Causes · Coeliac Disease · Crohn’s Disease · Bile Salt Malabsorption · Brush Border Enzyme Deficiency · SIBO · Radiation Enteritis · Eosinophilic Enteritis · Lymphoma · Tropical Sprue · Lymphangiectasia · Protein-Losing Enteropathy · NSAID Enteropathy Chronic Diarrhoea in Adults | Dr. Nasser 6

7. Pancreatic Causes · Chronic Pancreatitis · Pancreatic Carcinoma · Cystic Fibrosis Chronic Diarrhoea in Adults | Dr. Nasser 7

8. Functional Causes · Irritable Bowel Syndrome (IBS) Chronic Diarrhoea in Adults | Dr. Nasser 8

9. Endocrine Causes · Hyperthyroidism · Diabetes · Hypoparathyroidism · Addison’s Disease · Hormone-secreting Tumours (VIPoma, Gastrinoma, Carcinoid) Chronic Diarrhoea in Adults | Dr. Nasser 9

10. Systemic Causes · Drug Effects · Alcohol · Abetalipoproteinaemia · Advanced Liver Disease · CVID · Amyloidosis Chronic Diarrhoea in Adults | Dr. Nasser 10

11. Miscellaneous Causes · Surgical Resections (Short Gut Syndrome) or Bypass · Faecal Impaction (Overflow Diarrhoea) Chronic Diarrhoea in Adults | Dr. Nasser 11

12. Evaluation Introduction · Most cases can be evaluated in outpatient. · Red flags require urgent assessment. Chronic Diarrhoea in Adults | Dr. Nasser 12

13. Red Flags · Rapid Weight Loss · Dehydration · GI Bleeding · Anaemia · Severe Abdominal Pain Chronic Diarrhoea in Adults | Dr. Nasser 13

14. Urgent Assessment · Tachycardia · Dehydration · Fever · Hypotension Chronic Diarrhoea in Adults | Dr. Nasser 14

15. Inpatient Management · IV fluids, electrolytes · IV antibiotics if fever · Abdominal X-ray · Surgical consult · Sigmoidoscopy if needed · Transfusion if necessary Chronic Diarrhoea in Adults | Dr. Nasser 15

16. Evaluation Approach · Start with common and serious causes. · Stepwise evaluation if initial tests negative. Chronic Diarrhoea in Adults | Dr. Nasser 16

17. History – Part 1 · Duration >4 weeks · ≥3 stools/day · Nocturnal symptoms less likely in functional disorders · Blood in stool may indicate IBD, malignancy, or ischaemia Chronic Diarrhoea in Adults | Dr. Nasser 17

18. History – Part 2 · Weight Loss/Failure to Thrive · Abdominal Pain · Constipation alternating with diarrhoea · Nausea/Vomiting · Haematochezia/Melaena · Skin Changes Chronic Diarrhoea in Adults | Dr. Nasser 18

19. History – Part 3 · Steatorrhoea · Abdominal Distention/Bloating · Flatulence · Borborygmi · Anorexia · Increased Infections Chronic Diarrhoea in Adults | Dr. Nasser 19

20. Medication History · Laxatives · PPIs · NSAIDs · Quinine · Antibiotics (beware C. difficile) · Chemotherapies Chronic Diarrhoea in Adults | Dr. Nasser 20

21. Physical Examination · Skin rashes (Dermatitis Herpetiformis, Erythema Nodosum, Pyoderma Gangrenosum) · Lymphadenopathy or abdominal masses · Blood on rectal exam indicates mucosal lesion Chronic Diarrhoea in Adults | Dr. Nasser 21

22. Lab Evaluation – Basics · FBC, Electrolytes, Glucose, LFTs · CRP · TFTs · Coeliac Serology (IgA-tTG) · IgA Level · Haematinics (B12, Folate, Ferritin) Chronic Diarrhoea in Adults | Dr. Nasser 22

23. Lab Evaluation – Stool Tests · Faecal Calprotectin (rules out IBD, may be elevated in cancer, infection, NSAIDs) · Stool for Ova, Cysts, Parasites & Culture Chronic Diarrhoea in Adults | Dr. Nasser 23

24. Endoscopy · Colonoscopy with biopsy · Duodenal biopsy if Coeliac suspected · Negative colonoscopy reassures patient Chronic Diarrhoea in Adults | Dr. Nasser 24

25. Urgent Endoscopy · Evidence of GI Blood Loss · Anaemia · Significant Weight Loss Chronic Diarrhoea in Adults | Dr. Nasser 25

26. Common vs Uncommon · Common: IBD, IBS, Coeliac, SIBO, Drug Effects · Uncommon: Malignancy, Amyloidosis, CVID, etc. Chronic Diarrhoea in Adults | Dr. Nasser 26

27. Common: Ulcerative Colitis History: Haematochezia, tenesmus, frequent low-volume diarrhoea; family history. Exam: Non-specific, extraintestinal manifestations Investigations: Colonoscopy + biopsy; X-ray if toxic megacolon; Faecal Calprotectin Chronic Diarrhoea in Adults | Dr. Nasser 27

28. Common: Microscopic Colitis History: Coeliac increases risk; voluminous diarrhoea; mild pain, fatigue Exam: Non-specific Investigations: Colonoscopy + biopsy; IgA-tTG; OGD if Coeliac suspected Chronic Diarrhoea in Adults | Dr. Nasser 28

29. Common: Infectious Enteropathy History: Acute onset, travel, sick contacts, immunosuppression Exam: Non-specific; may have systemic manifestations Investigations: Stool cultures, O&P; duodenal biopsy if HIV suspected Chronic Diarrhoea in Adults | Dr. Nasser 29

30. Common: IBS History: Chronic, no alarm features, stress-related, bloating, pain relieved by defecation Exam: Mild distention/tenderness Investigations: Colonoscopy normal, IgA-tTG normal, breath tests for SIBO/lactose Chronic Diarrhoea in Adults | Dr. Nasser 30

31. Common: Drug Effects History: On offending drug Exam: Non-specific Investigations: Trial discontinuation, improvement indicates cause Chronic Diarrhoea in Adults | Dr. Nasser 31

32. Common: Faecal Impaction History: Severe constipation, overflow diarrhoea, cramping, gas Exam: Hard faecal mass on rectal exam Investigations: Abdominal X-ray Chronic Diarrhoea in Adults | Dr. Nasser 32

33. Common: Coeliac Disease History: Family/personal autoimmune disease; diarrhoea, pain, weight loss, bloating Exam: Dermatitis Herpetiformis Investigations: IgA-tTG; duodenal biopsy; capsule endoscopy Chronic Diarrhoea in Adults | Dr. Nasser 33

34. Common: Crohn's Disease History: Chronic abdominal pain, bloating, weight loss; family history Exam: Non-specific; masses, fistulae, skin lesions Investigations: Colonoscopy + biopsy; small bowel follow-through; faecal calprotectin Chronic Diarrhoea in Adults | Dr. Nasser 34

35. Common: Bile Salt Malabsorption History: Ileal resection >50cm or idiopathic Exam: Surgical scars may be present Investigations: SeHCAT test; trial cholestyramine; low-fat diet Chronic Diarrhoea in Adults | Dr. Nasser 35

36. Common: Brush Border Enzyme Deficiency History: Diarrhoea after ingesting offending substance Exam: Non-specific Investigations: Elimination diet; hydrogen breath test Chronic Diarrhoea in Adults | Dr. Nasser 36

37. Common: SIBO History: Diabetes, surgery, Coeliac, Crohn's; bloating, cramping, diarrhoea Exam: Non-specific Investigations: Breath test; trial antibiotics Chronic Diarrhoea in Adults | Dr. Nasser 37

38. Common: Pancreatic Insufficiency History: Pancreatitis, alcohol, CF; gradual diarrhoea Exam: Non-specific Investigations: Faecal Elastase; imaging; enzyme trial Chronic Diarrhoea in Adults | Dr. Nasser 38

39. Common: Alcohol History: Excessive intake Exam: Smell, intoxication, liver stigmata Investigations: Blood alcohol; LFTs; ultrasound Chronic Diarrhoea in Adults | Dr. Nasser 39

40. Common: Hyperthyroidism History: Autoimmune disease; weight loss, heat intolerance Exam: Tremor, goitre, tachycardia Investigations: TSH low; Free T4/T3 high Chronic Diarrhoea in Adults | Dr. Nasser 40

41. Common: Diabetes History: Known DM; nausea, early satiety Exam: Neuropathy, nephropathy, retinopathy Investigations: HbA1c, plasma glucose; motility studies Chronic Diarrhoea in Adults | Dr. Nasser 41

42. Uncommon: NSAID Enteropathy History: NSAID use; watery/bloody diarrhoea Exam: Non-specific Investigations: Colonoscopy; capsule endoscopy; cessation of NSAID Chronic Diarrhoea in Adults | Dr. Nasser 42

43. Uncommon: Infiltrating Malignancy History: Rapid weight loss, anaemia, pain, haematochezia Exam: Cachexia, pallor Investigations: CT Abdomen/Pelvis; Endoscopy + biopsy Chronic Diarrhoea in Adults | Dr. Nasser 43

44. Uncommon: Protein-Losing Enteropathy History: Edema, weight loss, rectal bleeding, recurrent infections Exam: Cachexia, pallor, oedema Investigations: Stool Alpha-1-Antitrypsin; Endoscopy Chronic Diarrhoea in Adults | Dr. Nasser 44

45. Uncommon Causes Part 2 · GVHD: Post bone marrow transplant; biopsy for diagnosis · Hodgkin/Non-Hodgkin Lymphoma: Abdominal pain, weight loss, night sweats; CT + biopsy · Tropical Sprue: Endemic areas; duodenal biopsy Chronic Diarrhoea in Adults | Dr. Nasser 45

46. Uncommon Causes Part 3 · Lymphangiectasia: Diarrhoea, steatorrhoea, oedema; alpha-1-antitrypsin, CT lymphangiography · Hypoparathyroidism: Fatigue, cramps; low PTH, low Ca · Addison's Disease: Fatigue, weight loss, hyperpigmentation; ACTH stim test Chronic Diarrhoea in Adults | Dr. Nasser 46

47. Uncommon Causes Part 4 · Gastrinoma/VIPoma/Carcinoid: Flushing, weight loss; fasting gut hormones, 5-HIAA, Octreotide scan · Abetalipoproteinaemia: Infancy poor growth; absent serum beta-lipoprotein Chronic Diarrhoea in Adults | Dr. Nasser 47

48. Uncommon Causes Part 5 · Advanced Liver Disease: History of liver disease; low-fat/MCT trial · CVID: Recurrent infections; low Ig levels · Amyloidosis: Multiple myeloma, inflammatory disease; biopsy Chronic Diarrhoea in Adults | Dr. Nasser 48

49. Radiation Enteritis/Colitis History: Abdominal radiation; haematochezia common Exam: Non-specific Investigations: Faecal occult blood; colonoscopy (telangiectasia, friability) Chronic Diarrhoea in Adults | Dr. Nasser 49

50. Eosinophilic Enteritis History: Pain, nausea, diarrhoea; allergies/food sensitivities Exam: Non-specific Investigations: Endoscopy biopsy >20 eosinophils/hpf; serum eosinophils Chronic Diarrhoea in Adults | Dr. Nasser 50

51. Chronic Ischaemic Colitis History: Older, vascular disease, antihypertensives; cramping pain, haematochezia Exam: Abdominal tenderness; blood on rectal exam Investigations: Colonoscopy, CT Chronic Diarrhoea in Adults | Dr. Nasser 51

52. Surgical Bypass/Resection History: Major GI surgery; short gut/dumping Exam: Abdominal scars Investigations: History, check B12, Iron levels Chronic Diarrhoea in Adults | Dr. Nasser 52

53. Summary & Key Takeaways · Chronic diarrhoea has vast differential · Stepwise approach · History, physical, basic labs first · Red flags for urgent care · Faecal calprotectin helps distinguish IBD vs IBS · Endoscopy + biopsy cornerstone Chronic Diarrhoea in Adults | Dr. Nasser 53

54. Chronic Diarrhoea in Adults A systematic approach to evaluation, diagnosis, and management. Prepared by: Dr. Nasser