GIT 3 Dr. Basu MD

Topic Ischemic bowel disease Hirschsprung disease (congenital mega colon) Meckel diverticulum Diverticular Disease Intestinal obstructions Volvulous, hernia Intussuseption Angiodysplasia.

Ischemic bowel disease Etiology Cause by sudden (acute) complete obstruction of the ‘blood flow’. Transmural infarction All layers are involved, gangrene. Clinical: mimic perforation.

Etiology Mesenteric Arterial thrombosis: sources= MI, IE, paradoxical embolism. Venous thrombosis= hypercoagulable states.

Morphology Common in Splenic flexure Severe, acute abdominal pain and tenderness. Peristaltic sounds diminish or disappear, and Spasm creates board-like rigidity of the abdominal wall. No free air in abdomen ( a feature of perforation)

Hirschsprung disease About 50% of familial cases are a consequence of mutations in the RET gene. Incidence: 1: 5000/8000 live birth Area of constriction : is the aganglionic segment. Proximal portion to that area: undergoes progressive dilation and hypertrophy

Aganglionic segment

Diverticula

True diverticula

False diverticula

Diverticulum Meckel diverticulum Rule of 2 ( 2%, 2 inch, 2 ft away from ilioceacal jn.), produce peptic ulcer disease. Diverticular Disease Blind pouch leading off the alimentary tract. Produce diverticulitis,diarrhea.

Meckel diverticulum: Vitelline duct produces this. Study other similar picture Present in anti mesenteric border. Mucosa contain gastric parietal cells.

Study other similar picture Diverticular Disease Study other similar picture Site: Most common site is the left side of the colon, with the majority in the sigmoid colon. Age : adult

Diverticular Disease Out pouching of the colon mucosa If Infection present = call it diverticulitis ( acute pain in left lower abdomen with leukocytosis). Discomfort, constipation, distention. Rectal (lower GI) bleeding.

Intestinal obstruction Causes: Intussusception, Herniation (umbilical or inguinal), Adhesion between loops of intestine- from peritonitis. Volvulus formation.

Hernia Def: The protrusion of an organ or structure into surrounding tissues. Inguinal hernia: bulges in the groin area become more prominent when coughing, straining, or standing up. They are often painful, and the bulge commonly disappears on lying down. Can cause intestinal obstruction!

Volvulus Def: is a loop of the bowel whose nose has twisted on itself . Etiology : may be spontaneous C/F: sudden abdominal pain, distension, and absolute constipation. Cannot introduce scope after certain distance per rectum. Complications: Ischemia, gangrene

INTUSSUSCEPTION INTUSSUSCEPTION Proximal segment Invaginate (telescoped) into the immediately distal segment of bowel. Cause: without any reason or rotavirus infection (child). Intra luminal mass ( adult).

Clinical : Sudden pain abdomen Telescoped intestine Intra luminal mass - arrow. Clinical : Sudden pain abdomen Current jelly stool. Sausage shaped mass in abdomen.

Clinical of obstruction

Clinical of obstruction A high obstruction = severe vomiting, no passage of stool, Distension, ? a mass palpable. Low obstruction= Distension, ? Mass palpable, no passage of stool/ flatus (absolute constipation). Acute obstruction= colicky pain (increased peristalsis). Gradual obstruction= tumor= insidious, over some weeks. Symptoms may gradually worsen. Diameter of stool will gradually decrease.

Note pad

Miscellaneous Angiodysplasia Arteriovenous malformation. Cecum and rt. Colon. C/F: episodes of rectal bleeding. Associated with Osler-weber-rendu and CREST syndrome Osler-weber-rendu Heredetary telangectesis ( lips, tongue, finger), Autosomal dominant.

Next topic Acute appendicitis HEMORRHOIDS Peritonitis

Acute appendicitis******* Cause→ Obstruction ( by fecalith, a gallstone, tumor, or ball of worms (oxyuriasis vermicularis). Clinical feature → Pain localizing to the right lower quadrant. Morphology → Gross and micro: Exudate and trans mural acute inflammation. Lab → Leukocytosis ( due to reactive myeloid hyperplasia) Tumor of → appendix Carcinoids and Mucinous tumors.

Leukemoid reaction = reactive myeloid hyperplasia = accelerated release of myeloid cells from the BM (reserve pool).

Trans mural acute inflammation Exudates on serosa with congested blood vessels

HEMORRHOIDS Hemorrhoids are variceal dilations of the anal and perianal venous plexuses. Cause: Constipation ( by cocaine), strain on stool, and pregnancy, after child birth. Clinical : fresh blood during defecation (pain in external type).

Peritonitis Cause: appendicitis, ruptured peptic ulcer, pancreatitis, bile, acute salpingitis [PID], dialysis. c/f: acute abdominal pain and gurding, which are exacerbated by moving the peritoneum, Rebound tenderness .

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