It's All About the Bowels

One more week of classes, then a week off for studying, and then it's our big exam for the semester. I don't know what's worse, having to write 5 exams in potentially completely unrelated subject areas you've covered during the semester or having one exam on everything you've done in the semester. I guess with one exam you get it all done and over with, but what if you have a bad day?

This accumulation of knowledge is really starting to get to me. New information is getting processed but at the same time, older information is being wiped away to make room for the more recent stuff. I'm at that point where I feel like I'm getting this error saying, "Disk full. Please insert a new disk."

I'm all about the mnemonics to remember stuff. Here are few more that I've come across or made up myself during the last few weeks of GI:

SECS causes bloody diarrhea (invasive bacteria)

Salmonella typhi - fecal-oral transmission
Enteroinvasive Escherichia coli - uncooked hamburger and swimming water
Campylobacter (eg. C. jejuni) - uncooked meat, esp poultry
Shigella dysenteriae - fecal-oral transmission


In a severe attack of ulcerative colitis, you get...HEAPS oF feces

Hb < 10 g/dL
ESR > 30 mm/hr
Albumin < 30 g/L
Pulse > 90 bpm
Stools > 6/day with blood
o
Fever > 37.5ºC


DOMES for diarrhea

Dysmotility

• eg. Thyrotoxicosis, IBS
  

Osmotic

• Food ingestion --> increased solute drag --> greater than 500 mL stool/day
• Disappears with fasting
• eg. lactose intolerance, magnesium antacids, gastric surgery

Malabsorption

• Voluminous, bulky, fatty, pale, smelly, floating, difficult to flush stools --> steatorrhea (more than 7 g fat in a 24 hr stool collection)
• eg. Coeliac disease, chronic pancreatitis, previous gastrectomy
  

1. Lipolytic phase defects (eg. pancreatic enzyme deficiency)
   
2. Micellar phase defects (eg. bile salt deficiency)
   
3. Mucosal defects (eg. diseased epithelial lining)
   
4. Delivery phase defects (eg. inability to transport fat from cells to lymphatics)
   

Exudative

• Inflammation of colon --> small volume, frequent, bloody and/or purulent stools
• eg. IBD, colon cancer

Secretory

• High volume, no pus/blood, not excessively fatty, diarrhea that persists when fasting.
• Net secretion > net absorption
• Causes
• Infection (eg. E. coli, S. aureus, Vibrio cholerae)
  
• Hormonal conditions (eg. vasoactive intestinal polypeptide-secreting tumor, Zollinger-Ellison syndrome, carcinoid syndrome)
  
• Villous adenoma