What Else Is Fine? (1)
Alice tilted her head at my words.
“Pseudomembranous colitis.”
She was sitting at the ward station, gazing at me with puzzled eyes, as if wondering what kind of story I was spinning right after getting back. But what could I do? The moment vacation ended, an unsolved case had jumped out at me.
“Antibiotics causing pseudomembranous colitis? First I've heard of it.”
As James senior had mentioned, it was already known in this era that antibiotics could trigger diarrhea. But the fact that they caused pseudomembranous colitis specifically? That hadn't been properly established yet. At any rate, it wasn't clear-cut.
James senior was listening quietly from the side. He seemed to have other work waiting.
I pressed on with my explanation. “Lots of cases where diarrhea hits a few days after antibiotics, right? There are studies on it too.”
“Sure, but isn't that allergies or side effects? Feels different from straight-up causing pseudomembranous colitis...”
Alice scratched her head. Pseudomembranous colitis and plain diarrhea weren't the same thing. In simple terms, it was colitis with a false membrane—like scabs forming over wounds in the gut. They cropped up everywhere, and with the intestines in that state, diarrhea was inevitable.
“Yeah, it's different.”
“But... why a bacterial infection from antibiotics? If anything, you'd think fewer bugs.”
The principle wasn't that complicated.
“The colon's packed with bacteria to begin with. Antibiotics don't wipe them all out.”
“Right?”
“When antibiotics kill off a bunch in the gut, weird ones start proliferating. Some of those trigger pseudomembranous colitis after antibiotic use.”
Alice squinted for a moment. “That's just a hypothesis.”
“It is.”
As Alice said, the studies proving it wouldn't come until later in the '70s. It was underexplored territory, which made it a prime research opportunity. Have I ever been wrong?
“I get what you're saying. But how do we even test a hypothesis like that...”
Next up: treating the patient's colitis. The fix was straightforward, but it wasn't my patient, so I couldn't just prescribe. I'd need permission. Shouldn't be too hard, right? The attending seemed pretty set in his ways, though.
I eyed the gastroenterology professor. Henry Harrington—the attending for that pseudomembranous colitis patient I'd reviewed earlier. Younger-looking than I'd expected.
He scowled at my pitch. “What kind of nonsense is that?”
First real pushback in a while. Harrington was a skeptic.
“To treat the patient's diarrhea, I think we should start oral vancomycin.”
“Hold on—you're saying antibiotic-induced diarrhea, and your fix is more antibiotics?”
It was a tricky paradox. No wonder the cause and treatment for pseudomembranous colitis weren't nailed down even in 1970.
I nodded. “Yes.”
“Ah... I get that the ward attending's a first-year IM resident. You know we can't just throw antibiotics around, right? Especially vancomycin.”
“Oral vancomycin's fine.”
Harrington crossed his arms. “What else is fine?”
“Vancomycin's bioavailability. Oral form is 0%—it doesn't enter the bloodstream at all, even swallowed, so it barely affects the patient's systemic condition.”
He shook his head, still displeased. Or maybe he just enjoyed a good academic spar? His expression stayed grave either way.
“Fine, say oral vanco's bioavailability is 0%. Why give a patient a drug that doesn't absorb?”
Bioavailability meant the percentage of a drug that hits the bloodstream after dosing. Varied wildly by med.
The reason it helped here? Simple.
“The pseudomembranous colitis bacteria are in the gut, not circulating in the blood.”
Checkmate. Harrington opened his mouth as if to retort, then shut it, pondering.
That's right. The more he mulled, the more it'd sink in.
“Alright. I get it—so explain why antibiotic-induced diarrhea gets fixed with an antibiotic.”
“We need something to kill the bacteria causing the pseudomembranous colitis, and oral vanco's the only option. IV won't reach the gut—no effect.”
Only vanco reliably took out Clostridium difficile. Problem was, IV vanco didn't touch the gut. Oral only.
Medicine could be needlessly convoluted sometimes.
“The idea of a specific bacteria causing it is weird enough... Isn't this just a drug side effect?”
Nope.
How to frame it?
“No. The patient's labs show neutrophil-driven bacterial enteritis—no eosinophils involved.”
“That tracks, at least.”
I shrugged. “Keep it simple, Professor. Suspected bacterial enteritis, so antibiotic to kill the bugs. Pick one with low bioavailability to minimize systemic exposure.”
“Oral vancomycin again.”
I nodded, brimming with confidence this time. Convinced yet?
“Yes.”
Harrington threw up his hands in mock surrender. “You've cooked up a detour to justify treating your wild-ass hypothesis. Where do you even get these ideas?”
“I thought about it hard.”
“Fine... What's giving a little vanco? Week's course, then observe.”
“Thank you.”
I bowed to the professor. Permission granted—now we could treat.
Wonder if Harrington would dive into research on this. I'd spoon-fed him the full rundown, from mechanism to pharmacology.
He'd catch on once he saw the results.
Oral vancomycin usually kicked in within a day—symptoms starting to ease. For a severe case like this, not instant recovery, but I'd hoped for a quick response.
Now it was Harrington's rounds. I tagged along.
The patient lay still in bed, face still pained. Better than yesterday, maybe?
“Hello there.”
“Hi.”
“How's the diarrhea?”
“Well... Way better than yesterday. Still some belly pain, but much improved.”
Harrington nodded. “Good to hear. And the gallbladder surgery site?”
“Not sure. Feels okay, I think.”
“Alright, rest up.”
The patient rolled over; we redrew the curtain and stepped out.
In the ward hallway, Harrington spoke up.
I listened closely.
“Thought it was full of holes.”
Happens sometimes. Diseases don't always play by a human doctor's logic.
Antibiotics kill bacteria? Sure, but some only boom once competitors are cleared out.
Or IV drugs that flat-out skip certain tissues.
As you'd seen.
But hey, diseases gonna disease.
“Yeah?”
“Didn't buy it at all. But no eosinophils, just like you said. Fever's down big-time since starting oral vanco.”
As expected.
“Glad it's working.”
“If oral vanco works, means there's a specific bug causing pseudomembranous colitis. One killed by oral vanco.”
“Clostridium difficile.”
“That—”
Harrington cut himself off.
Didn't matter if it sounded plausible. We'd test it medically.
“Ha... Why Clostridium difficile? Peek at a future textbook or something?”
Sharp guy. Specifically, its toxin attacked the gut lining, causing diarrhea. With so many bacteria in the colon, it flew under the radar until late in the '70s.
I mulled my explanation.
“Difficile—it's in the name. Means 'hard to culture,' right? Among known bugs, not normal gut flora but with baseline antibiotic resistance? Options are slim.”
He scowled again. “Kid, medicine ain't theoretical physics. You don't deduce this stuff brooding at a desk...”
But I'd be right. Wanna bet?
“Run the test—it'll show. Anaerobic culture'll grow C. diff, minimal others.”
“Ugh. Fine.”
Harrington let out a dry chuckle.
Anyway, he'd have to check. No avoiding it.