1. Chronic diarrhea is defined as persistent changes in stool consistency and increased stool frequency lasting over 4 weeks. 2. The causes of chronic diarrhea include secretory, osmotic, steatorrheal, inflammatory, dysmotility, and iatrogenic factors. 3. The approach to a patient with chronic diarrhea involves obtaining a detailed history and physical exam, followed by screening tests and further testing depending on the results to identify the underlying cause and guide management.

1. CHRONIC DIARRHEA
Preceptor : Dr Nishav Raj Shahi
Presenter : Dr Parash mani Bhatta

2. Duration : 30 minutes
Objectives : At the end of session , participants will be able to
know how to approach the case of chronic diarrhea

3. CONTENT
1. DEFINITION
2. ETIOLOGY
3. APPROACH
4. MANAGEMENT

4. Definition :
Persistent alteration of stool consistency and increase stool
frequency of greater than 4 weeks duration.

5. Causes of Chronic diarrhea
1) Secretory :
-Derangement in fluid and electrolytes transport.
-Watery and non bloody large volume fecal outputs that are
typically painless and persist with fasting.
-No fecal osmotic gap.
Fecal osmotic gap:
serum osmolarity (290 mosmol/kg) – { 2 * ( fecal sodium +
potassium concentration)}

6. • Exogenous stimulant laxatives( senna, cascara , bisacodyl)
• Chronic ethanol ingestion.
• Endogenous laxatives ( dihydroxy bile acids)
• Bowel resection, disease or fistula ( decrease absorption) –
Worsens with eating.

7. • Bile acid diarrhea : resection of < 100cm of terminal ileum ,
dihydroxy bile acids may escape absorption and stimulate
colonic secretion (cholerheic diarrhea).
- Bile acids are functionally malabsorbed from a normal
appearing terminal ileum

8. • Hormone producing tumor ( carcinoid, VIPoma, Medullary
cancer thyroid , mastocytosis, gastrinoma, colorectal villous
adenoma)
• Addison disease
• Oral angiotensin receptor blocker , olmesartan.

9. 2 ) Osmotic:
-Poorly absorbable osmotically active solutes draw enough fluid into lumen
to exceed reabsorptive capacity of colon.
-Fecal osmotic gap ( >50 mosmol/L)
-Fecal water output increases .
-Less voluminous .
-Caeses with fasting/discontinuation of causitive agent.
• Osmotic laxatives( Magnesium, phosphate and sulfate)
• Lactase deficiency
• Gluten and FODMAP intolerance
• Nonabsorbable carbohydrates ( sorbitol, lactulose, polyethylene glycol)

10. 3) Steatorrheal:
-Steatorrhea is defined as stool fat exceeding normal
7g/day
• Intraluminal maldigestion( pancreatic exocrine insufficiency-
chronic pancreatitis, bacterial overgrowth, bariartic surgery,
liver disease)
• Mucosal malabsorption ( celiac sprue, whipple’s disease,
infections, abetalipoprotenemia, drug induced enteropathy,
ischemia)
• Post mucosal lymphatic obstruction

11. 4) Inflammatory:
-Characterized by pain , fever and bleeding.
• Idiopathic inflammatory bowel disease ( crohn’s disease,
ulcerative colitis)
• Infection ( Selective IgA deficiency or common variable
hypogammaglobulinemia, eosinophilic gastroenteritis, history
of clostridiodes infection, invasive bacteria , viruses and
parasites, Brainerd diarrhea)
• Gastrointestinal malignancies
• Radiation injury

12. 5) Dysmotility
• Irritable bowel syndrome.
• Carcinoid syndrome.
• Hyperthyroidism.
• Drugs ( prokinetic agents).
• Postvagotomy.

13. 6)Factitial:
• Munchausen ( self injury for secondary gain)
• Eating disorders

14. 7) Iatrogenic:
• Cholecyctectomy
• Ileal resection
• Bariartic surgery
• Vagotomy, fundoplication

15. Approach to the patient
History
Characterstic symptoms:
Stool characterstics-
Fat malabsorption -Greasy stools that float and malodorous.
Inflammatory cause : presence of visible blood.
Carbohydrate malabsorption (lactose):
watery diarrhea , excess flatus and bloating .

16. • Duration of symptoms , nature of onset ( sudden or gradual )
• Diarrhea during fasting or at night suggests secretory or
inflammatory diarrhea .
• Voluminous watery diarrhea- disorder in small bowel.
• small volume frequent diarrhea - disorders of colon.
• Presence of bloody diarrhea favors colonic versus small bowel
disorder.

17. Stool characterstics and determining
their source
source : medscape
Stool characteristics Small bowel Large bowel
Appearance Watery Mucoid and/or bloody
Volume Large Small
Frequency Increased Highly increased
Blood Possibly positive but never
gross blood
Commonly gross blood
pH Possibly <5.5 >5.5
Reducing substance Positive Negative
WBCs <5/high power field >10/high power field
Serum WBC Normal Leukocytosis

18. • Weight loss and fever, joint pain , mouth ulcers , eye redness
indicate IBD
• Association of stress and depression : Irritable bowel
syndrome(IBS)
IBS – chronic abdominal pain and diarrhea , constipation or
normal bowel habits alternating with either diarrhea or
constipation

19. Physical examination
• Features to suggest malabsorption or inflammatory bowel
disease such as anemia , dermatitis herpetiformis , edema or
clubbing.
• Look for autonomic neuropathy, collagen vascular disease in
pupils , orthostasis, skin, hands or joints?
• Abdominal mass or tenderness

20. • Abnormalities of rectal mucosa , rectal defects or altered anal
sphincter functions?
• Mucocutaneous manifestation of systemic disease:
- dermatitis herpetifomis ( celiac disease),
- erythema nodusum ( ulcerative colitis),
- flushing (carcinoid) or
-ulcers for IBD or celiac disease?

21. • Evaluation of alarm features : suggestive of underlying organic etiology.
• Age of onset after age 50
• Rectal bleeding or melena,
• Nocturnal pain or diarrhea
• Progressive abdominal pain
• Unexplained weight loss, fever, systemic symptoms
• Laboratory abnormalities( iron deficiency anemia, elevated C-reactive
protein or fecal calprotectin)
• Family history of inflammatory bowel disease or colorectal cancer

22. Source: uptodate

25. Complications
• Rapid dehydration
• Intussusception
• Gram-negative sepsis
• Hemolytic-uremic syndrome (HUS)
• Hemorrhagic colitis

26. Management of chronic diarrhea
Step 1 :
Exclude iatrogenic problem: medication , surgery
Step 2 :
A) Blood per rectum - Colonoscopy + biopsy
B) Fatty diarrhea – small bowel (imaging, biopsy, aspirate)
C) No blood , features of malabsorption- consider
functional diarrhea – dietary exclusion of lactose ,
sorbitol .

27. D) Pain aggravated before Bowel movement , relieved with
bowel movement , sense incomplete evacuation-
suspect irritable bowel syndrome
Limited screen for organic disease: Hematology, chemistry, CRP, ESR, Iron,
folate, B12, TTG-igA, C4, Stool for excess fat, calprotectin
Low hemoglobin,
Albumin: abnormal
MCV,MCH: excess fat in
stool
Low serum
potassium
Stool volume,
osmotic, pH;
laxative screen;
hormonal screen
Colonscopy +
biopsy
Small bowel: x-ray, biopsy
aspirate: stool 48h fat
Stool fat >20g/day:
pancreatic function
Stool fat 14-20g/day:
search for small bowel
cause
Normal and
stool fat <
14g/day
Titrate
treatment
to speed of
transit

28. Screening test all normal
Opiod treatment plus follow
up
Persistent chronic
diarrhea
Full gut transit 48 hour stool bile acid
Titrate treatment
to speed of transit
Bile acid
sequestrant

29. Treatment
For all patients with chronic diarrhea fluid and electrolyte
replacement is a must.
Curative
• Resection of colorectal cancer
• Antibiotic administration for Whipple’s disease or tropical sprue,
or discontinuation of drug.

30. Supressive
• Elimination of dietary lactose for lactase deficiency
• Elimination of Gluten for celiac sprue,
• Glucocorticoids for idiopathic IBDs,
• Bile acid sequestrants for bile acid malabsorption,
• PPIs for gastric hypersecretion of gastrinomas,
• Octreotide for malignant carcinoid syndrome,
• Indomethacin for medullary carcinoma thyroid,
• Pancreatic enzyme replacement for pancreatic insufficiency.
• Ppi-proton pump inhibitors

31. Empirical therapy :
• Mild/moderate watery diarrhea - Opiates such as
diphenoxylate or loperamide .
• Severe diarrhea- codeine or tincture of opium
(Avoid Antimotility agents in severe IBD because of risk of toxic
megacolon )
• Clonidine- control of diabetic diarrhea .
• Ondensetron, Alosetron - relieve diarrhea and urgency in IBS.
• Also rifaximin and eluxadoline for IBS
• Replacement of fat soluble vitamins in patients with chronic
steatorrhea.
IBD-inflamatory bowel disease , IBS- irritable bowel syndrome

32. SOURCE
• Harrison’s Principles Of Internal Medicine,
-20th edition.
• UpToDate.
• Medscape.