Week 10: Gastrointestinal Pathologies Part 2

Question 1

Crohn’s Disease

Answer 1

• chronic inflammatory disorder of unknown cause most often in young adults
• usually in terminal ileum of small bowel and/or proximal portion of the colon (Crohn’s colitis)
• involves all layers of the GI tract
• may have healthy and diseased areas interspersed
• diffuse inflammation causes bowel loops to bind together
• ulceration is common, as well as fistulas to bowel and other organs

Question 2

Small Bowel Obstruction

Answer 2

• blockage of the small intestine
• due to adhesions from previous surgeries, peritonitis, hernias, intussusception, volvulus, tumours or vascular insufficiency
• may produce ischema with subsequent necrosis of bowel segment, sepsis and peritonitis

Question 2

Adynamic (Paralytic) Ileus

Answer 2

• fluid and gas (and any bowel contents) do not progress normally through a non-obstructed small (or large) bowel
• can be post op, peritonitis, medication, trauma
• part or all of small/large bowel fills to being peristalsis
• localized ileus = small part of small or large bowel affected
• colonic ileus = large bowel affected
• treatment: NG tube, IV fluids

Question 2

Localized Ileus

Answer 2

• isolated distended loop (sentinel loop)
• due to adjacent inflammatory process
• radiographic appearance: one very distended loop

Question 2

Colonic Ileus

Answer 2

• excessive gaseous distention of bowel
• often see massive distention of cecum
• can look like mechanical obstruction (BE to rule out obstruction)
• radiographic appearance: retention of large amounts of gas and fluid in dilated small and large bowel with no demonstrate point of obstruction

Question 2

Inguinal Hernia

Answer 2

• some of the abdominal contents, usually part of the small bowel, protrude through a weak are in the abdominal wall at the inguinal canals (one on either side of groin)
• peritoneal sac bulges out too and surrounds the protruded contents
• the hernia may persist outside or slide in and out of the abdomen
• can cause constriction and/or ishcemia of protruding part

Question 3

Intussusception

Answer 3

• telescoping of one part of the intestinal tract into another because of peristalsis
• can compromise the vascular supply = ischemic necrosis of the intussuscepted bowel
• most common site in children: ileocecal valve
• major cause of bowel obstruction in children

Question 4

Hemangiomas - Benign Vascular Tumours

Answer 4

• occur anywhere along the GI tract, most often in the small bowel, then large bowel and rectum
• may cause bleeding
• radiographic appearance: contrast displacing mass on contrast study

Question 5

Diverticulum/Diverticulosis

Answer 5

• diverticulum (single)/diverticula (plural) are out pouchings (herniations) of mucosa and submucosa through the muscular layers at points of weakness in the bowel wall
• lack of fibre and water in the digestive track can lead to development
• many diverticula = diverticulosis, may cause lower GI bleed
• diverticula can occur in esophagus or duodenum

Question 5

Polyps

Answer 5

• benign neoplasms that project into the lumen of the bowel
• mostly asymptomatic but certain types can become cancerous
• colonoscopy can find and remove
• found mostly in descending and sigmoid colon

Question 6

Diverticulitis

Answer 6

• complication of diverticular disease (diverticulosis), especially in the sigmoid region
• retained fecal matter trapped in diverticulum can lead to inflammation and perforation
• diverticulitis is inflammation of diverticula
• may produce peri-diverticula abscess
• may form fistula to adjacent organs

Question 6

Diverticulitis Radiographic Appearance

Answer 6

• similar to diverticulosis, barium study demonstrates round or oval out pouching projecting beyond lumen (usually multiple)
• contrast leaving from diverticula
• abscess soft tissue mass
• sawtooth configuration
• can cause narrowing and rigidity of long section of colon with gradual transition to normal

Question 7

Sessile (Flat) Polyp

Answer 7

• irregular lobulated surface
• lie flat against colon wall
• more likely to be malignant
• inductive of cancer if over 2 cm in diameter, causes puckering/indentation/retraction at site or interval growth on subsequent exams

Question 7

Pedunculated Polyp

Answer 7

• smooth surface with a long thin stalk
• more likely to be benign

Question 8

Ulcerative Colitis

Answer 8

• an inflammatory bowel disease, often begins in rectosigmoid area
• may spread to involve entire colon, rarely involves small bowel
• usually involves only the mucosal layer of the colon
• alternating periods of remission and relapse
• can become cancerous
• symptoms: bloody diarrhea, abdominal pain, fever and weight loss

Question 9

Toxic Megacolon

Answer 9

• a complication of ulcerative colitis
• extreme dilation of part or all of large colon
• can lead to spontaneous bowel perforation
• due to perforation risk, BE contraindicated
• radiographic appearance: huge air filled colon

Question 10

Colorectal Cancer

Answer 10

• cancer of the colon and rectum, usually in the rectum and sigmoid
• peak age 50-70
• needs early diagnosis for best outcome
• several type
• can cause polypoid mass or surround colon
• ulceration common
• may have multiple carcinomas or metachronous cancer
• can metastasize

Question 11

Annular Colorectal Carcinoma

Answer 11

• annual lesions surround the bowel from outside
• most common bowel cancer
• starts from flat plaques of tumours (saddle lesions), easily missed of exams
• usually in sigmoid
• radiographic appearance: BE will demonstrate apple-core or napkin ring filling defect

Question 12

Large Bowel Obstruction

Answer 12

• blockage of large bowel usually due to primary colon cancer
• could be from diverticulitis or volvulus
• less sever than small bowel obstruction
• form more slowly with fewer fluid and electrolyte disturbances
• causes increased pressure (closed loop) and risk of perforation, especially of cecum

Question 13

Volvulus

Answer 13

• twisting of the bowel on itself that may lead to abdominal obstruction
• most frequently involves the cecum and sigmoid colon

Question 13

Malrotation Of Bowel/Colon

Answer 13

• twisting of the bowels, like volvulus bit occurs during fetal development
• may be problematic or not, depending upon severity
• volvulus symptoms may be first sign of malrotation: abdominal distention, pain, vomiting, constipation, bloody stools
• radiographic appearance: abnormal location of bowel on image

Question 14

Imperforate Anus (Anal Atresia)

Answer 14

• congenital lack of anal opening
• often associated with a distended bowel
• radiographic appearance: multiple dilated bowel loops filled with gas, absence of rectal gas