Small Intestine and Appendix

Question 1

Small Bowel Obstruction

Answer 1

Cause: postsurgical adhesions, hernia, metastatic peritoneal cancer (ovarian or colon), SMA syndrome, strictures (Crohn’s disease, radiation, ulcers, adenocarcinoma, GI stromal tumors, lymphoma), foreign body, gallstone ileus, phytobezoar, intussusception
High risk for strangulation: leukocytosis, tachcardia, fever, localized abdominal tenderness
Features: high pitched bowel sounds, dehydration
1. proximal: colicky pain, bilious frequent large emesis, epigastric tenderness
2. distal: intermittent to constant pain, low volume emesis, diffuse progressive tenderness, distention, obstipation
3. closed loop: progressive pain, prominent emesis, diffuse progressive tenderness
4. colon/rectum: continuous pain, intermittent vomiting, diffuse tenderness, marked distention, obstipation
Dx: abdominal X-ray (dilated loops of bowel, air fluid levels), CT, contrast studies (if partial obstruction)
lactic acidosis may mean bowel ischemia
Tx: IV isotonic fluids, reduction of hernia, watch and wait, surgery

Question 2

Paralytic Ileus

Answer 2

Features: minimal abdominal pain, N/V, obstipation, distension, decreased/no BS, gas in small intestine and colon.

Question 3

Crohn’s Disease

Answer 3

chronic, transmural inflammatory condition of alimentary tract but can affect skin, eyes, mouth, joints, biliary system.
Histology: creeping fat, fistulas, cobblestoning/skip lesions, terminal ileum, transmural, malabsorption, granulomas
Features: abdominal pain, diarrhea, weight loss, waxing and waning, RLQ pain, perianal involvement, conjunctivitis, uveitis, iritis, pyoderma gangrenosum, erythema nodosum, ankylosing spondylisis, arthritis, sclerosing cholangitis, granulomatous hepatitis, vasculitis, aphthous stomatitis
deficiencies of B12, Vit A/D/E/K.
Dx: colonoscopy or barium enema
Tx: antidiarrheals (loperamide), vitamin replacement, sulfasalazine, corticosteroids, azathioprine, 6-mercaptopurine, methotraxate, cyclosporine, tacrolimus, mycophenolte mofetil, infliximab, adalimumab, certolizumab, probiotics
surgery if have perforation, fibrotic stricture, SBO, fistula

Question 4

Mesenteric Ischemia

Answer 4

from impaired blood flow:
1. SMA embolism
2. SMA thrombosis
3. SMV thrombosis
4. nonocclusive mesenteric ischemia
pain with eating = SMA stenosis
Features: pain out of proportion to PE, a fib, atherosclerotic disease, metabolic acidosis
Dx: mesenteric angiogram, high res CT
Tx: rapid resuscitation, correct metabolic abnormalities, abx, embolectomy/stent/bypass/ex lap, heparin

Question 5

Adenocarcinomas

Answer 5

most common in duodenum
Features: obstruction, weight loss, occult bleeding, anemia
Tx: resection

Question 6

Carcinoid Tumors

Answer 6

from Kulchitsky cells in crypts of Lieberkuhn.
appendix>SI (ileum)
Features: obstruction from desmoplastic rxn in adjacent bowel, anorexia, fatigue, weight loss
Carcinoid syndrome: cutaneous flushing, bronchospasm, intestinal cramping, diarrhea, vasomotor instability, pellagra-like skin lesions, R sided valvular heart disease, increased 5-HIAA and serotonin, hepatic metastasis
Dx: laparotomy
Tx: resection

Question 7

Lymphoma

Answer 7

most commonly in ileum (peyer’s patches).
ex: MALToma associated with H pylori
Features: abd pain, weight loss, fatigue, malaise, perforation, hemorrhage, obstruction, intussusception
Dx: CT or contrast studies show nodularity and thickening of bowel wall
Tx: resection and chemoradiation

Question 8

Gastrointestinal Stromal Tumors

Answer 8

GIST
mesenchymal tumors of GI
Features: obstruction, bleeding, perforation, elevated c-kit
Tx: wide excision, tyrosine kinase inhibitors (sunitinib, imatinib)

Question 9

Meckel’s Diverticulum

Answer 9

remnant of embryonic vitelline duct
2% population, 2 years old, 2:1 M:F, 2 types of mucosa (gastric and intestinal), 2 feet of ileocecal valve
Features: hemorrhage, ileus, intussusception, diverticulitis, perforation
Dx: technetium-99 pertechnetate scan
Tx: resection

Question 10

Malrotation

Answer 10

congenital issue with intestinal rotation
Features: small bowel volvulus causing ischemia and necrosis, bilious emesis, distention, tenderness, shock
Dx: radiographic UGI series
Tx: emergent laparotomy

Question 11

Short Bowel Syndrome

Answer 11

<60cm means TPN, small bowel transplant, intestinal lengthening

Question 12

Acute Appendicitis

Answer 12

Cause: fecolith, virus
Features: periumbilical pain to RLQ pain localization, anorexia, N/V, low grade fever, leukocytosis, tenderness at McBurney’s point, Rovsing’s sign, pain with gentle movement, pain on palpation of LLQ
Dx: US, CT
Tx: appendectomy, abx, fluids