Download Malabsorption syndrome

Approach to diarrhea
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What is diarrhea?
What is acute diarrhea?
What are its causes?
What is chronic diarrhea?
What are its causes?
What is small bowel diarrhea?
What is large bowel diarrhea?
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Causes of acute diarrhea
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Infections
Toxins
Inflammation (acute on chronic)
Drug induced
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Causes of chronic diarrhea
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HIV
TB
Opportunistic infections
Inflammatory bowel disease
Irritable bowel syndrome
Malabsorption syndrome
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Malabsorption syndrome
Dr. Ravi Vaswani MD PGDBEME PGDHPE
Professor, Department of Internal Medicine
Yenepoya Medical College, Mangalore
MALABSORPTION SYNDROME
• This occurs when the normal digestion and
absorption of food is interrupted
• PATHOPHYSIOLOGICAL (MECHANISM):
– Intraluminal stage
– Intestinal stage
– Lymphatic transport
– Decreased co-factors/nutrients
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A) Intraluminal stage: Impaired hydrolysis and
solubilization of nutrients in the small intestine.
• Impaired fat absorption:
– Pancreatic lipase is necessary for triglyceride hydrolysis
in duodenum
– Pancreatic enzyme deficiency leads to fat malabsorption
– Inactivation of pancreatic lipase by low gastric luminal pH
• Interruption of enterohepatic circulation of bile salt –
impaired micelle formation – fat malabsorption.
• Absorption of fat soluble vitamins may be impaired
as well.
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Impaired protein absorption:
• Hydrolysis of polypeptides occurs mainly in
small intestine by action of pancreatic
enzyme trypsin, chymotrypsin
• Deficiency of pancreatic proteases –
impaired protein absorption
• Diseases like:
– Chronic pancreatitis
– Cystic fibrosis
– Ca. pancreatic resection
– Protein malnutrition
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B) Intestinal stage
• Abnormalities of small intestinal mucosa
– Lactase deficiency (congenital or acquired)
• Result – malabsorption of lactose.
• Acquired:
– Coeliac disease
– Crohn’s disease
– Infective enteritis
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• Impaired epithelial cell transport:
• Many diseases cause loss of intestinal
surface area leading to malabsorption of
many nutrients
– Coeliac disease
– Tropical spure
– Extensive surgical resection
– Drugs
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C) Lymphatic transport:
• Lymphatic obstruction – fat malabsorption
– Intestinal lymphangiectasia
– Tuberculous enteritis
– Intestinal lymphoma
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D) Decreased availability of ingested
nutrients and cofactors for
absorption
• Vitamin B12 malabsorption if intrinsic
factor is deficient. e.g. gastrectomy,
antiparietal cell Ab
• Bacterial overgrowth –can bind B12
• Patient infected with fist tapeworm – B12
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History
• Diarrhea/steatorrhoea
• Weight loss
• Symptoms of anaemia
• Diarrhoea – bulky, floating, malodorous stool, difficult
to flush
• Weight loss – may be profound, usually associated
with anorexia
• Anaemia – B12, iron, folate malabsorption
• Patient may complain of dizziness, dyspnoea and
fatigue
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Important historical points
• Recent travel - giardiasis
• Drug abuse/multiple blood transfusions or ethanol
abuse
• Surgical resection
– small bowel
– gastric
• Malabsorption + chronic lung disease = cystic
fibrosis
• Fever + weight loss = TB, lymphoma.
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O/E:
Normal.
Pallor
- muscle wasting
Sign of vitamin deficiency
glossitis – B deficiency
ecchymoses
parasthesia
tetany
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Investigations:
General:
- CBC
- Blood film
- Ca.
- B12, folate
- Iron study
- LFT, PT, PTT
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Investigations:
Specific:
Tests of fat absorption:
Quantitative fecal fat
Patient should be on daily diet containing 80-100
grams of fat.
Fecal fat estimated on 72 H collection.
6 grams or more of fat/day is abnormal.
May be due to: - Pancreatic
- Small intestinal
- Hepatobiliary disease
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14C-Triolein
Test:
Is triglyceride which is hydrolysed by pancreatic
lipase.
 absorption of metabolism ↑ 14CO2
lung
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Tests for pancreatic function:
1) Bentiromide test:
Chymotrypsin
PABA + pepside
PABA  absorbed and conjugated in liver
 urine excretion
2) Schilling test
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3) Pancreatic stimulation test
Secretin stimulation –
4) Radiographic techniques:
- Plain abdominal X-ray
- U/S abdomen
- ERCP
- CT abdomen
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Carbohydrate absorption test
1) Hydrogen breath test
Hydrogen excretion ↑ in
bacterial overgrowth
small intestinal malabsorption
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Carbohydrate absorption test
2) D-xylose test
5-carbon sugar  excreted unchanged in urine
25 grams given
Urine collected for 5 hours
Normally 25% is excreted
In patients with fat malabsorption, this test
differentiates pancreatic from small intestinal
malabsorpton.
D-xylose is normal in pancreatic disease
Serum level of D-xylose at 1-2 hours after ingestion
can
be measured.
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Test for bacterial overgrowth:
1) Intestinal aspiration and culture
2) Breath test
3) C-D xylose breath test
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1) Radiography of small intestine:
Barium swallow and follow-through – to see
- Blind loop
- Stricture
- J. diverticular
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2) Intestinal mucosal biopsy:
- using crossby capsule
- endoscopy
Coeliac disease:
- Villous atrophy
Tropical spure:
- short villi and increased lymphocyte
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Selection of tests in evaluation malabsorption
Quantitaive fecal fat
Normal
Abnormal
D-xylose test
Abnormal
Normal
14 C-D-xylose test
Abd. Radiograph
Bentiromide test
CT-abd.
Normal
Small intestinal
Bx
Abnormal
• Jej culture
• Tetracyclin
•Then repeat breath test
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Classification of Malabsorption Syndrome
A. Inadequate digestion:
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Postgastrectomy steatorrhea.
Exocrine Pancreatic insufficiency.
Reduced bile salt concentration in intestine
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Liver Disease
Cholestasis
Bacterial over growth
Interruption of enterohepatic circulation of bile salt.
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B. Inadequate absorptive surface:
• Resection
• Diseased intestine
C. Lymphatic obstruction.
e.g Lymphoma
D. Primary mucosal defects.
• Crohn’s disease
• Coeliac disease
• Tropical Sprue
• Disaccharide Deficiency
• Lymphoma
• TB
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Malabsorption due to bacteral over growth of small
bowel
Normal small intestine is bacterial sterile due to:
– Acid
– Int. peristalsis (major)
– Immunoglobulin
Cause of bacterial growth.
e.g.
– Small intestinal diverticuli
– Blind loop
– Strictures
– DM/ Scleroderma
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Pathophysiology
1)
Bacterial over growth: Metabolize bile salt resulting in
deconjugation of bile salt
  Bile Salt
 Impaired intraluminal micelle formation
 Malabsorption of fat.
2)
Intestinal mucosa is damaged by
 Bacterial invasion
 Toxin
 Metabolic products
 Damage villi  may cause total villous atrophy.
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Clinically:
 Steatorrhea
 Anaemia
 B12 def.
Reversed of symptom after antibiotic treatment.
Diagnosis:
 Breath test
 Cxylose test
 Culture of aspiration (definitive)
Treatment: Antibiotic
 Tetracyclin
 Ciproflexacin
 Metronidazole
 Amoxil
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Celiac sprue
• Originally thought to be caucasian
• Now worldwide distribution
• Aka non-tropical sprue, celiac disease & gluten
enteropathy
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Etiology
• Environmental: Gliadin in gluten (wheat,
barley and rye)
• Immunologic: auto-immune antibodies (antigliadin, anti-endomysial)
• Genetic: HLA-DQ2 or HLA-DQ8 allele
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Clinical features
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May appear with introduction of cereals into an infant's diet
Although spontaneous remissions often occur during the second decade of life
that may be either permanent or followed by the reappearance of symptoms over
several years
Alternatively, symptoms may first become evident at almost any age throughout
adulthood
In many patients, frequent spontaneous remissions and exacerbations occur
Symptoms range from significant malabsorption of multiple nutrients, with
diarrhea, steatorrhea, weight loss, and consequences of nutrient depletion
(anemia and metabolic bone disease), to the absence of gastrointestinal symptoms
despite evidence of the depletion of a single nutrient (e.g. iron or folate deficiency,
osteomalacia, edema from protein loss)
Small-intestinal biopsy
Serologic studies (e.g. antiendomysial antibodies, tissue transglutaminase [tTGJ],
deamidated gliadin peptide).
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Clinical features
• Celiac disease is considered an "iceberg" disease
• Few have classical symptoms and manifestations
related to nutrient malabsorption along with a varied
natural history
• Onset can occur between first year till eighth decade
• More have "atypical celiac disease”, with
manifestations not obviously related to intestinal
malabsorption (anemia, osteopenia, infertility, and
neurologic symptoms)
• Even more persons have "silent celiac disease“ asymptomatic despite abnormal small - intestinal
histopathology and serologies
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