Diseases of the small intestine

1. Diseases of the small intestine Malabsorption Functions of the GIT Digestion begins with: Fragmentation by stomach Secretion of pancreatic juice, bile ,water Brush border enzymes digestion Enterocytes absorption Site of absorption: whole or specific area. Maldigestion or malabsorption

2. Classification of malabsorption • Inadequate digestion. • Pancreatic dis • Intraluminal bile salt deficiency • Specific causes as disaccharidase deficiency • Inadequate absorption • Inadequate absorption surface • Mucosal cell defect • Diffuse disease of the small intestine

3. others • Lymphatic obstruction • Drug induced • Multiple mechanisms • Hyper absorptive state

4. Clinical picture of malabsorption • Diarrhea ,steatorrhea • Picture of failure to thrive • Wt loss &malnutrition • Abdominal distention and edema • Anemia • Paresthesia • Bone pain • Bleeding tendency • Nocturia • milk intolerance • Clubbing of fingers, pallor ,fair hair &skin.

5. Investigations • Fecal fat analysis • Test of pancreatic exocrine function • Bentiromide test • Abdominal x-ray and CT scan • Xylose absorption excretion test • Radiological test • Small intestinal biopsy • Schilling test • Breath test • Specific malabsorption for B12 ,albumin ,Vit.K, minerals

6. Celiac disease • Pathogenesis: • Gluten peptide is taken by epith. Cells • Deamidation of gluten by tissue trasglutaminase give product which can fit the antigen binding site on APC. • Present the combination to CD4+ • Triggering of TH1 response to IL-1, IFN gamma , TNF alpha. • Lymphocye infiltration • Crypt hyperplasia • Villous atrophy.

7. Clinical feature • In infants • Older children • In adult : • Clinical features: Non specific as malaise ,anorexia—iron, folate or Ca deficiency Diarrhea& steatorrhea—water, electrolyte ,&fat malabsorption. Wt loss ---fat &CHO malabsorption. Abdominal pain &bloating—distended bowel loops. Aphthus ulcers –gluten sensitivity and Vit deficiency. Nausea & vomiting Itching spots +ve family history Oedema---hypoproteinemia

8. Pigmentation ,tetany &bone pain—Vit D &Ca deficiency . • Bleeding tendency---Vit K deficiency • Night blindness ---Vit A deficiency • Anemia ----iron and folate deficiency • Myopathy ---osteomalacia.

9. investigations • Duodenal biopsy. Total or subtotal villous atrophy. • Antibodies • Antigliadin Ab-IgA • Antiendomysial antibodies. • Tissue transglutaminase assay *blood test and biochemistry

10. management • Gluten free diet • Correct all deficit nutrients • Rarely need steroid or immunosuppressive therapy

11. Failure to response to therapy • Dietary compliance • Other dis accompany coeliac dis • Accompanied by T cell lymphoma

12. Dermatitis herpetiformis • Picture of malabsorption +skin rash (intensive itching blisters) • Treatment: • Gluten free diet +depsone 100-150 mg\day

13. Tropical sprue Chronic progressive malabsorption In tropical areas Viruses or toxin forming bacteria,E.choli,klebsiela,enterobacter First acute then chronic Diarrhea ,fever ,glositis, ankle odaema,,abd distention ,folate deficiency anemia, remision and relapse. Treated by tetracycline for 28 days ,folic acid, leave tropics

14. Bacterial overgrowth small intestine • Increase number of coliform bact 10*8-10*10\ml in duodenum &jujenum. • Due to decrease acidity of stomach or impaired intestinal motility. • Jujenal diverticulosis, DM diarrhea, systemic sclerosis, hypogammaglobulenaemia. • Clinical features watery diarrhea & steatorrhea, Vit B12 deficiency and increase folate • Consumption of the bile salt • Tetracycline,metronidazole&ciprofloxacin

15. Whipple’s disease • Gram +ve bacilli-Tropheryma whipplei. • Foam macrophage infiltration in lamina properia. • Gastrointestinal manifestations • Musculoskeletal • Cardiac • Neurology • Pulmonary • Hematology • Fever, pigmentation • Treatment-Co-trimoxazole, ceftriaxone 6-12 m.

16. Ileal resection • Vit B12 and salt deficiency • Bile salt malabsorbtion. • Lithogenic bile gall stone. • Normally oxalate bind calcium and bile salt absorbed. • Treated Vit B12,colestyramine&Al(OH)3.

17. Radiation enteritis • Acute short, oedematous villi& crypt abscess –resolve or oblitrative endarteritis • Chronic fibroblastic proliferation, adhesion ,ulcers, strictures ,fistula &obstruction. • Treated by symptomatic, local steroid, antibiotics ,nutritional supplement colistyramine,treat bleeding spots • No surgery.

18. Chronic intestinal pseudo obstruction • Defect of smooth muscles of small intestine. • Alteration of diarrhea and constipation. • Bacterial over growth. • Treat underlying cause

19. NSAIDs small intestinal toxicity • Erosion ,ulceration ,mucosal web,stricture &sub mucosal fibrosis • Diagnosis by laparatomy

20. Meckel’s diverticulum • Occur with in 100 cm of ileum ,3% ,5 cm long ,contain gastric, colonic ,pancreatic or endometrial tissue. • Complicated by melena ,bleeding or intestinal obstruction. • Diagnosis by Tc99-pertechnate which concentrate in gastric mucosa

21. Lactose intolerance • Glucose & galactose • fermentation

22. Food allergy • Types