Gastrointestinal system Dr.Sura Obay AL-Dewachi M.B.Ch.B- M.Sc Pathology/Hematology

Peptic ulcer Digestion of the mucosa of the affected part (stomach, esophagus, first part of small intestine) by acidic gastric juice. Ulcer in the stomach is known as gastric ulcer while ulcer in the first part of small intestine is known as doudenal ulcer.

According to the duration, degree of penetration and degree of healing , peptic ulcer is divided in to: 1.Acute peptic ulcer. 2.Chronic peptic ulcer.

Etiology of peptic ulcer 1.Gastric hyper acidity. 2. Infection by H-pylori 3.Imbalance of mucosal defense defense mechanism. 4.NSAID 5. others, genetics, gastritis, smoking, alcohol,stress due to serious illness, etc.

Acute gastric ulcer Gross: small less than 1 cm ,multiple , affect any part of the stomach, involve mucosa and submucosa and heal without fibrosis Rarely it may perforate and bleed

Chronic gastric ulcer Usually single rarely two ,The lesser curvature is most commonly affected .Large in size up to 5 cm rounded or oval , its surface is covered by necrotic materials and has an indurated base.The indurations involve the entire thickness of the wall of the stomach, it may be adherent to surrounding organ and may form fistula.

Chronic gastric ulcer (cont) Microscopically: the surface is covered by fibrinoid materials. Layer of granulation tissue Layer of fibrous tissue Interruption of muscular layer Endarteritis of affected vessels

Complications of chronic gastric ulcer 1. Heamorrhage; leading to haematemesis and malena .Chronic oozing lead to anemia 2.Perforation: result in passage of food, gastric juice , bacteria to peritoneal cavity leading to peritonitis 3.Fibrosis: fibrosis lead to pyloric obstruction , hour glass stomach 4.Malignant changes: Rare less than 1%

Duodenal ulcer Usually affect the first part of the duodenum Grossly and microscopically the same as chronic gastric ulcer The complications are similar except that malignant changes is extremely rare

Zollinger-Ellison Syndrome Rare condition in which hyper gastrinemia from a pancreatic or duodenal tumor (gastrinoma) stimulate extreme gastric acid secretion which in turn cause peptic ulceration . Gastric and duodenal ulcers are often multiple . Ulceration may occur in unusual locations like jejunum.

Irritable bowel syndrome Functional gastro intestinal disorder characterized by chronic and relapsing abdominal pain and altered bowel habits (diarrhea,constipation) in abscence of specific organic pathology. Affected ages between 20 and40 years. Significant female predominance.

Pathophysiology of IBS No physiologic mechanism unique to IBS has been identified, however, multiple factors have been considered to play a role: Abnormal gut motility Visceral hypersensitivity Diet Psychological stress and emotional events.

Despite very real symptoms, no gross or microscopical abnormalities are found in most IBS patients. Diagnosis of IBS is symptoms based and reliant on clinicians judgment. Prognosis of IBS is related to symptoms duration. Longer duration correlated with reduced liklihood of improvement.

Diarrheal diseases Diarrhea is a common manifestation of many intestinal diseases, including those due to infection , inflammation, ischemia, malabsorption, and nutritional deficiency.

Malabsorptive diarrhea A condition arising from abnormality in absorption of food nutrient across the GIT affecting single or multiple nutrients depending on the cause This abnormality may be in: Digestion (Intraluminal) Absorption (Mucosa) Transport (postmucosal)

Malabsorption syndrom Clinically : it lead to : 1. Deficiency state:e.g. Anaemia hypoprotenaemia etc. 2. Gastrointestinal symptom: e.g. Abdominal discomfort, diarrhea, bulky pale stool (Steatorrhea)

Malabsorption syndrome Classification: 1.Primary malabsorption syndrome: A.Celiac disease (gluten sensitive enteropathy) B.Idiopathic steatorrhea C.Tropical spru.

Malabsorption syndrome Secondary malabsorption syndrome: A. Chronic intestinal disease B. Abnormal bacterial proliferation C. Inadequate digestion D. Others

Malabsorption: Investigation Investigations are guided by symptom & signs: Stool exam Blood tests Radiological tests (Barium meal , CT, MRI) Small intestinal biopsy.

Villous atrophy It is the most important pathological changes in malabsorption syndrome and can be classified in to : 1. Partial villous atrophy (P.V.A) 2. Subtotal villous atrophy (S.V.A.)

Partial villous atrophy (P.V.A) The villi are shorter and broader than normal. The crypts are enlarged and hyperplastic. The epithelium show degenerative changes the lamina propria is infiltrated by plasma cells and lymphocytes.

Subtotal villous atrophy (S.V.A) It is more severe than P.V.A, There is sever shortening of the villi .The mucosa looks flat.

Celiac disease (Gluten sensitive enteropathy) A genetically determined abnormal immune response to gluten Affect children Characterized by severe steatorrhea The mucosal lesion is S.V.A .at the proximal jejunum become less severe i.e P.V.A. Distally Withdrawal of gluten from diet result in clinical and morphological remission

Complication of celiac disease Failure to thrive Increased incidence of intesinal lymphoma and adenocarcinoma Associated with skin lesions e.g dermatitis hepitiformis, rosacia etc.

Idiopathic steatorrhea (Adult form of celiac disease) Affects adult patients The mucosal lesion is P.V.A. But it is more extensive The response to gluten free diet is less satisfactory

Tropical spru This type of malabsorption is common in tropical and subtropical area Affects children and adults Characterized by chronic diarrhea, severe anemia and folic acid deficiency The mucosal lesion is P.V.A. rarely S.V.A. Broad spectrum antibiotics and removal from tropical area is helpful Gluten free diet has no effect

Secondary malabsorption 1.Chronic intestinal diseases e.g. T.B, Amyloidosis. Crohns disease etc. 2. Abnormal bacterial proliferation: e.g. in blind loop syndrome, Giardia infestation 3.Inadequate digestion: e.g. liver diseases, billiary diseases etc 4. Others e.g. enzyme deficiency drugs , radiotherapy etc.

Inflammatory bowel disease of unknown etiology 1.Crohns disease 2.Ulcerative colitis

Crohns disease I.B.D . Of unknown etiology but diet smoking, infection , defective inflammatory response and immune mechanism has been suspected. Affect any age but 3rd and 4th decade. Clinically: abdominal pain, intestinal obstruction.it has prolonged coarse with remission and relaps attacks.

Pathology of Crohns disease Gross 1.Affect any part of GIT specially terminal ileum, with skip lesion (Regional ileitis). 2.The affected part is thick ,edematous, and hard. The lumen is narrowed, the mucosa ulcerated, nodular and have cobble stone appearance with fissure in its wall, leading to fistula. The serosa is thick and edematous. The regional L.N. is enlarged.

Pathology of crohns disease Microscopically: Chronic inflammatory changes involving the entire thickness of the wall i.e transmural with formation of noncaseating epitheloid granuloma. Lymphatic obstruction explain the edema , goblet cell hyperplasia with increased mucus secretion. The L.N. show epitheloid granuloma

Complication of Crohns disease Malabsorption specially Vit.B12 Fistula formation Intestinal obstruction Carcinoma may complicate crohns dis.