Clinical GI physiology

Question 1

Intestinal blind loop syndrome

symptoms to cause

Answer 1

diarrhea, steatorrhea
fat maldigestion and malabsorption
due to decrease in intraluminal BA
due to deconjugation of bile acids facilitated by anaerobic bacteria
impaired gut peristalsis –> bacterial overgrowth

Question 2

Inflammatory bowel disease 炎症性腸病

Answer 2

Ulcerative Colitis (colon rectum)
Bloody diarrhea
T: NSAIDS, glucocorticoid therapy, colectomy

Crohn’s Disease (any part of GI, terminal ileum)
Abdominal pain, weight loss, less bloody diarrhea
T: ileal resection –> reduce BA reabsorption at distal ileum –> BA to colon stimulate Cl-secretion tgt with Na+ and water loss –> secretory diarrhea

If BA is bound to resin e.g. cholestyramine, cannot stimulate colonic Cl-secretion or cause secretory diarrhea

Question 3

Appendicitis

Answer 3

acute abdominal pain in the lower right quadrant of the abdomen with elevated level of alpha-amylase,
–> peritonitis
use antibiotics/ appendectomy

Question 4

Irritable Bowel Syndrome

Answer 4

abnormally increase GI motility associated with emotional stress young women, nonspecific diarrhea bloating lower abdomen pain and cramps pain is relieved by moving the bowels
high fiber food, anti-diarrheal drug anti-depressants

Question 5

Pancreatic cholera

Answer 5

endocrine tumor of pancreas –> overproduction of VIP (GI peptide) stimulate intestinal secretion of fluid and electrolytes Cl- Na+ H2O
VIP also relax GI sphincter and cause vasodilation

Question 6

Gastroparesis胃輕癱

Answer 6

belching and vomiting
reduced gastric emptying
impaired vagal activity due to autonomous neuropathy in DM patients （糖尿病神經病變）or vagotomy in treating peptic ulcer disease.
T: Pyloroplasty (cut and weaken muscle in the pyloric area)

Question 7

Dumping Syndrome

Answer 7

Diarrhea: osmotic load placed in the small intestine
Duodenal ulcer: acid entry&raquo_space; neutralization
Hypoglycemia: early insulin secretion (hypoglycemia activate sympathetic –> sweating and palpitation)

Question 8

Prenicious anemia

Answer 8

RBCs are enlarged (large nucleated immature RBCs –> Megaloblast)
High gastrin level (without acid to trigger release of somatostatin from D cell which inhibit antral gastrin release)
autoimmune disease, antibodies against parietal cell (acid and Intrinsic factor)
IF is needed for B12 absorption in the ileum.
B12 is needed for RBC maturation in bone marrow

Question 9

Peptic ulcer disease

Answer 9

Duodenal Ulcer and gastric ulcer
associated with iron-deficiency anemia
Causes: H.pylori, Aspirin, NSAIDS, gastrinoma, stress, hypercalcemia
T: ompeprazole (propon pump inhibitor)， biopsy at endoscopy to check for maliganancy

Question 10

Gasteroenteritis

Answer 10

nausea, vomiting, weak, dizzy, hypokalemia, hypochloremia, metabolic alkalosis

Question 11

Chronic pancreatitis

Answer 11

Pain, steatorrhea, maldigestion, glucose intolerance, diabetes mellitus
Serum amylase or lipase levels may be normal in CP
Secretin stimulation test, CCK stimulation test
Causes: alcohol, hereditary, CF, repeated AP

Question 12

Acute pancreatitis

Answer 12

upper abdominal pain, alpha amylase and lipase increase
autodigestion
Gallstone and alcoholism causes premature activation of trypsinogen to trypsin inside the pancreas

Question 13

Jaundice

Answer 13

hyperbilirubinemia (high level of total bilirubin either in free or conjugated form)
liver disease e.g. liver cirrhosis, hepatitis, glucuronyl transferase deficiency
pre-hepative: excessive hemolysis
post-hepatic (obstructive): gallstone block bile excretion

Question 14

Lactose intolerance

Answer 14

Diarrhea, gas, cramps, Asian or African
Lacking brush border enzyme lactase
Lactose-H2 breath test

Question 15

Lysinuric protein intolerance

Answer 15

malnutrition, mild diarrhea
Basolateral membrane amino acid transport disorder, autosomal recessive
T: lysine infusion

Question 16

Hartnup’s disease/ cystinuria

Answer 16

hereditary deficiency of neutral amino acid transporter/ basic amino acid
the enterocyte can absorb amino acid normally if it is presented as small peptides or high-protein diet because oligopeptide cotransporter is normal

Question 17

Steatorrhea

Answer 17

foul-smelling floating fecal matter
inadequate luminal digestion and absorption of TAG
pancreatic exocrine insufficiency or lack of bile acids
pancreatitis, CF, celiac disease, gastrinoma

Question 18

Abetalipoproteinemia

Answer 18

build up of fat within the enterocyte

failure to make apo B prevents chylomicron formation can’t enter lymph

Question 19

Celiac disease

Answer 19

iron-deficiency induced anemia, diarrhea, weight loss and steorrhea, malabsorption
loss of intestinal villi
inflammation of intestinal villa caused by GALT
intolerance to gluten (gliadin)
secondary lactose intolerance due to lacking of lactase
T: withdraw gluten in diet, glucocorticoid therapy