Rectovaginal Fistula [Symptom]

This isn't a disease - just a symptom. But it's so distinctive that it deserves its own entry. Recall the purpose of this blog to recount the "cool, weird, fascinating, or just plain bizarre"? Well today's entry *DEFINITELY* qualifies as bizarre and weird. Perhaps most bizarre is just how emotionlessly the teacher mentioned it in class. Also, this merits a disclaimer:

*IF YOU ARE EASILY GROSSED OUT, DO NOT READ THIS ENTRY*

You've been warned :)

Short 'n Sweet: Full-thickness colonic ulceration leads to an anastamosis between it and the vaginal tract.

Background Anatomy&Physiology:

Our body's digestive tract can be thought of as a series of tubes (quite like the internet, per a certain Ted Stevens ;) ). Food starts in the mouth, then esophagus (hollow tube for swallowing), the stomach itself, then the small intestine (where most nutrients are absorbed), the large intestine or "colon"(which handles the remaining water) the rectum, which empties out into the anus (back-end). Each of these structures has an empty space in the middle through which food - or what's left of it - passes. A space like this is referred to as a lumen.

Now the walls of each of these structures are made of multiple different parts (not discussed fully here). Each layer having its own function. Needless to say, they all fit together quite nicely, and there's (for the most part) no branches, T-junctions, or other alternate paths for food to take as it gets squeezed down through the tube!

Next is the term "fistula". A fistula is an abnormal connection between two eptihelial-lined organs or tissue areas. If an artery - for example - had an abnormal direct connection to a vein, that would be a fistula. .  .more specifically an arterio-venous fistula.

Lastly, as most men and women eighteen and up know (actually most twelve and up, but who's counting?) the vagina opens up into a tube-like structure of its own - the vaginal tract.


What goes wrong:

So, we've got this normally-healthy wall of the colon or rectum right? But there are disease processes that can cause it to weaken and even form an ulcer - a hole through one or more layers. Sometimes the ulceration is so bad that it can go all the way through and form a fissure - a cut through *ALL* the layers, leading to a small hole in the colon-wall (or rectal wall, depending where it occurs along the path).

Now the body doesn't like open wounds like this, so naturally it tries to heal itself. However, sometimes, the healing leads it to "attach" to an adjacent structure. Sometimes this adjacent structure is a different part of the colon - entero-enteric fistula. Sometimes it's the skin - entero-cutaneous fistula. And sometimes, if you're unlucky, it's the vaginal tract - or an enterovaginal fistula (or Rectovaginal, if rectum affected).

What does this mean? It means that instead of the lumen of the colon/rectum just moving on towards the anus, part of the lumen branches off. . . leading to the vaginal tract, and the vagina.

An affected patient will pass some part of her 

stools and possibly even fart out of her vagina!

Treatment:

As scary/disconcerting as the symptoms are, in the grand scheme of things this isn't a very dangerous symptom/complication by itself. Obviously it's bad if left untreated, but a woman's not likely to "not notice" this for very long ;). Once it's diagnosed, surgery can correct the fistula, and detach or - if necessary - simply remove the affected portion of the colon.

But unlike all previous entries -as indicated by the title- this is a symptom, not the disease itself. It's something a disease *causes* that's a hint as to what's *REALLY* wrong. The real issue is to figure out what causd it in the first place. As we mentioned earlier, healthy colons don't spontaneously get deep-fissures through the side of their walls! One typical reason is a chronic illness known as Crohn's disease (one of the inflammatory bowel diseases), which in and of itself is something to be worried about.