Antibiotic-associated colitis—a difficile problem

It’s that time of year again—the time of year when everyone gets the sniffles, and everyone wants an antibiotic. Even folks who know better, who know intellectually that an antibiotic isn’t going to fix their viral illness still harbor a strong suspicion that it just might help—and it couldn’t hurt, right?

Well, I’ve got two words for ya’ll: eat shit.

No, I don’t mean that as an insult, I mean it quite literally. But you’ll have to keep reading to see what I’m talking about.

Many readers are aware of the problem of antimicrobial resistance—the phenomenon whereby bacterial diseases become resistant to antibiotics, a problem exacerbated by the profligate and inappropriate use of these agents. Another serious complication of antibiotic therapy is antibiotic-associated colitis (which also goes by the names “pseudomembranous colitis”, “Clostrium difficle colitis“, or simply “C diff colitis”.) This one is nasty. As diseases go, this is one you really, really don’t want. Really. Think I’m kidding? I’ve got two more words for you: toxic megacolon.

OK, let’s get down to details.

As you are probably aware, your colon is home to a large and diverse population of microorganisms. These usually-benign commensals are easily disturbed by antibiotic therapy. Antibiotics cause some species to die off, giving others room to stretch their legs. One of the bacteria species that normally doesn’t give us much trouble is Clostridium difficile. C. diff is resistant to many commonly used antibiotics, so when, for example, I give you cipro for your severe urinary tract infection, many colonic E. coli and other peaceful folks die off, and C. diff takes over their niche. When the C. diff population booms, things go down the crapper. Lots of things.

C. diff is a nasty critter. When the organism is stressed, for instance after it is no longer in your colon, it forms very hardy spores that are resistant to most common methods of disinfection. So one patient may have diarrhea, spores may be spread everywhere, and health care providers my walk these spores over to another patient’s room. C. diff spreads rapidly in hospitals and nursing homes. It’s horrid, painful, smells characteristically foul, and it can kill.

C. diff produces toxins that kill the cells that line your colon. When this happens, you can get very, very ill—diarrhea and high fever are only the beginning. The most feared complication of C. diff colitis is toxic megacolon, a condition where your colon swells to an inconveniently dangerous diameter, and you may become septic and die.

C. diff is, unfortunately, a predictable consequence of antibiotic therapy, but there is much that can be done. It disproportionately affects the sick and elderly in hospitals and other institutions, so infection control practices are vital. Since disinfectants don’t usually do the trick, vigorous hand washing, disposable gloves and gowns, and isolation from other patients is a must. And antibiotic use must be minimized.

C. diff is treatable, especially if the patient isn’t too sick to start with. It’s treated with antibiotics. Yes, as you surmised, that is a bit of a problem, and C. diff has a high recurrence rate.

There have been many novel suggestions to help prevent C. diff infections. Since C. diff is a problem of bacterial overgrowth, physicians have tried giving patients probiotics, that is, giving them oral doses of benign bacteria such as Lactobacillus. Results have not been encouraging. Another creative ploy exploits C. diff itself. There are strains of C. diff that are not toxogenic, and some studies of giving people non-toxogenic C. diff spores have been encouraging (but not that encouraging). But the cure that has given us one of the better understatements in the medical literature is fecal transplantation. A filtrate of stool, usually from a family member, is introduced into the stomach of the patient, usually by naso-gastric tube. According to one author, “in the absence of controlled trials, fecal transplantation remains unpopular for practical and aesthetic reasons.”

Antibiotic associated colitis due to C. diff is a growing problem, affecting nursing homes and hospitals across North America. It is also being seen more frequently outside of these settings in otherwise normal people. This disease only rarely occurs without exposure to antibiotics, so we can prevent it. Antibiotics are good—they save lives. But they are widely misused, and we need to help patients better understand that there are consequences to overusing these powerful tools.