Goljan makes a big point about classifying diarrhea into Invasive, Secretory and Osmotic. In his RR book, this classification is followed up by a page-long table listing the different bugs that cause diarrhea and specific features of each (eg, rotavirus is the MCC of diarrhea in kids and usually occurs in winter).

In this table, there is no attempt to group the different bugs into either the invasive or secretory types of diarrhea. I tried to group the bugs causing diarrhea into invasive/secretory diarrhea, but then wondered if there is any point to it. Does this neat classification of the mechanisms of diarrhea of any real clinical applicability? Is so, why didn't Goljan point out which were secretory and which were invasive in the table of bugs causing diarrhea (page 213, Table 17-4, 2004 Edition of Goljan's Rapid Review).

Goljan makes a big point about classifying diarrhea into Invasive, Secretory and Osmotic. In his RR book, this classification is followed up by a page-long table listing the different bugs that cause diarrhea and specific features of each (eg, rotavirus is the MCC of diarrhea in kids and usually occurs in winter).

In this table, there is no attempt to group the different bugs into either the invasive or secretory types of diarrhea. I tried to group the bugs causing diarrhea into invasive/secretory diarrhea, but then wondered if there is any point to it. Does this neat classification of the mechanisms of diarrhea of any real clinical applicability? Is so, why didn't Goljan point out which were secretory and which were invasive in the table of bugs causing diarrhea (page 213, Table 17-4, 2004 Edition of Goljan's Rapid Review).

Yeah, I definitely think there is a point, because the symptoms (bloody vs. watery) follow the type of infection and the bug. I think that there are only two major invasive types, one e coli and another that I cant remember.

No, E Coli causes secretory diahrea according to Goljan's RR. Robbins doesn't classify the diarrhea's in this way. Robbins as usual makes life complicated by coming up with "Deranged Motility", "Exudative Diseases" and a couple of others besides "Secretory diahrea".

So if it's important to know which diarrhea falls under which catagory (secretory/osmotic/invasive), how about some pointers on how this classification makes a clinical difference. Goljan sez that if there are no leukocytes in the diarrhea, it's not invasive and "you don't have to worry" (which I interpreted as meaning that it is self-limiting). What do you do if it is invasive?

Also, if someone could tell me which catagory these bugs fall in. They are in the RR table I mentioned in the OP.
Clostridium botulinum
Clostridium difficile
M. tuberculosis
the Salmonella bugs
Balantidium coli
Cryptosporidium parvum
Giardia (MCC cause of diarrhea in Russia! ;) )
...and the helminths...

No, E Coli causes secretory diahrea according to Goljan's RR. Robbins doesn't classify the diarrhea's in this way. Robbins as usual makes life complicated by coming up with "Deranged Motility", "Exudative Diseases" and a couple of others besides "Secretory diahrea".

So if it's important to know which diarrhea falls under which catagory (secretory/osmotic/invasive), how about some pointers on how this classification makes a clinical difference. Goljan sez that if there are no leukocytes in the diarrhea, it's not invasive and "you don't have to worry" (which I interpreted as meaning that it is self-limiting). What do you do if it is invasive?

Also, if someone could tell me which catagory these bugs fall in. They are in the RR table I mentioned in the OP.
Clostridium botulinum
Clostridium difficile
M. tuberculosis
the Salmonella bugs
Balantidium coli
Cryptosporidium parvum
Giardia (MCC cause of diarrhea in Russia! ;) )
...and the helminths...

There is more than one type of E.coli. Enterohemorrhagic E.coli does cause bloody diarrhea. There are a few other types (Enterotoxigenic, Enteroinvasive E.coli) that all have different mechanisms for causing diarrhea.

Yeah, I definitely think there is a point, because the symptoms (bloody vs. watery) follow the type of infection and the bug. I think that there are only two major invasive types, one e coli and another that I cant remember.

EIEC is the invasive strain of the E. Coli. The other invasive bug is Shigella, which attaches itself to the intestinal epithelium and penetrtes.

Shigella is more of a day care spread diarrhea, don't forget though that EHEC has shiga toxin as well.

yeah i thought shigella was the other. dont worry about classifying all the bugs. Just keep in mind the few that are invasive and present with bloody diarrhea. the rest you can get solely from history. (C difficile, Vibrio, etc.)

Goljan mentions in his lecture that Campylobacter jejuni is the MCC of invasive diarrhea with Shigella being the second most common. Hope this helps.

Could tell me which catagory these bugs fall in. They are in the RR table I mentioned in the OP.
Clostridium botulinum
Clostridium difficile
M. tuberculosis
the Salmonella bugs
Balantidium coli
Cryptosporidium parvum
Giardia (MCC cause of diarrhea in Russia! )
...and the helminths...

It's been a while and I unfortunately dont' have the book in front of me. However, it matters clinically and on exams b/c they will tell you whether it's secretory or bloody. This should narrow your differential down one way or another. For example, it may say has leukocytes and choices listed may be all secretory, except for one, etc. Dont' worry about every single one - worry about the big ones e-coli, camp, girar, salm, shig....THE BIG ONES THEY MAY ASK YOU TO IDENTIFY BY SOMETHING THAT IS CLASSIC FOR THEM (eg. mountain water - girardia)....FOR THE SMALL ONES YOU WILL GET OUT OF THE HISTORY. So KNOW the most common things about big ones. This is usually very helpful on USMLE. For example, infants - rotavirus, drinking mountain water - girardia (also see fat in diarrhea).

E-coli - usually MC cause of traveller's diarrhea. If invasive, then its' Ecoli 0157:H7.

Shigella, salmonella, campylobacter are invasive. Campylobacter infection mimics appendicitis.

Also realize the mechanism - for secretory (eg cholera - what is the mech). For invasive ones how is the mechanism similar for each of them. Hope that helps a little.

Could tell me which catagory these bugs fall in. They are in the RR table I mentioned in the OP.
Clostridium botulinum
Clostridium difficile
M. tuberculosis
the Salmonella bugs
Balantidium coli
Cryptosporidium parvum
Giardia (MCC cause of diarrhea in Russia! )
...and the helminths...

Dont wory about it. The symptoms tell you whether or not they are invasive or not. All are secretory, I think, although MAYBE giardia is considered invasive. But you wont be asked to define the type of diarrhea from the bug, you will likely get sy/sx that you recognize as pathogen-specific however.

Goljan mentions in his lecture that Campylobacter jejuni is the MCC of invasive diarrhea with Shigella being the second most common. Hope this helps.

And dont forget the Guillian-Barre association.

Dont wory about it. The symptoms tell you whether or not they are invasive or not. All are secretory, I think, although MAYBE giardia is considered invasive. But you wont be asked to define the type of diarrhea from the bug, you will likely get sy/sx that you recognize as pathogen-specific however.

Ok thanks man... one last thing: Invasive diarrhea will always be bloody right? No exceptions right?

this is a great thread.....my .02.....don't forget that salmonella is motile and can hide out in places like the gallbladder making you a longterm carrier :horns:

Ok thanks man... one last thing: Invasive diarrhea will always be bloody right? No exceptions right?

The only invasive diarrhea I would remember are the aforementioned C. Jejuni, Shigella, and EIEC E. Coli. They are all bloody.