A Third Recurrence: Choosing the Fourth Course
A third C. diff recurrence in eight months. The real gap in her history isn’t how many times she’s relapsed — it’s that the guideline-preferred antibiotic for recurrence was never actually tried.
Delia F., a 67-year-old retired postal worker who now spends most of her time caring for her grandchildren after school, has had Clostridioides difficile infection three times in the past eight months, each recurrence arriving within two to three weeks of finishing treatment. Her first episode followed a course of clindamycin for a dental abscess; both recurrences since have been treated with standard 10-day oral vancomycin, and both times her diarrhea resolved during treatment only to return shortly after the course ended. She has never received fidaxomicin, a fact that only became clear when the team reviewed her full medication history at this visit — her prior treating physicians had simply repeated what worked short-term the last time, without ever trying the guideline-preferred agent for recurrence specifically.
She is otherwise healthy, on no immunosuppressive medications, and increasingly exhausted by a cycle that has now cost her three separate weeks of illness this year and left her wary of leaving home between symptoms flaring. Her most recent stool toxin assay remains positive, confirming this is a genuine third recurrence rather than post-infectious irritable bowel, and the question in front of her care team is no longer whether she needs treatment — she plainly does — but whether the next step is another antibiotic course, however better-targeted than the ones already tried, or a transplant of donor gut flora meant to break the cycle at its actual mechanism rather than suppress it again temporarily.
What both prior vancomycin courses actually demonstrated, read together rather than as two isolated relapses, is that suppressing Clostridioides difficile directly can restore normal bowel function reliably — twice — without ever restoring the surrounding microbial community that would ordinarily keep the organism’s spores from germinating again once antibiotic pressure lifts. That distinction is the entire rationale behind considering fecal microbiota transplant here rather than simply repeating what worked before: a third antibiotic course, fidaxomicin included, treats the same visible symptom the last two courses already treated successfully; only rebuilding the flora addresses why the visible symptom keeps returning three weeks after the drug stops working on it — the reasoning behind van Nood et al.’s transplant trial, stopped early when the advantage over continued vancomycin proved too large to keep randomizing.
Gastroenterology and infectious disease, joint clinic visit
She meets the guideline threshold for FMT — two or more recurrences — and every additional antibiotic course we give her keeps disrupting the microbiome that’s the actual reason she keeps relapsing. I’d move to fecal microbiota transplant now rather than trying a fourth course of anything.
I want to name something the recurrence count is hiding: she’s had two antibiotics total, both vancomycin. She’s never actually received fidaxomicin, which showed a meaningfully lower recurrence rate than vancomycin in Louie et al.’s head-to-head trial, attributed to its narrower spectrum sparing more of the surrounding flora. Treating her as having "failed antibiotics" broadly, when she’s only failed one specific agent twice, undersells an option that’s genuinely still on the table.
That’s not a rejection of FMT—it’s a rebuttal to the idea that we’ve exhausted the antibiotic side of this before we actually have.
I don’t think you two are actually disagreeing about the destination, just the order. Start extended-pulsed fidaxomicin now — it genuinely hasn’t been tried — but book her FMT referral today rather than waiting to see if this course fails first. If it works, she’s spared the transplant. If it doesn’t, she loses no real time, because the next step is already scheduled instead of starting from zero after a fourth relapse.
Agreed: start extended-pulsed fidaxomicin today, and place the FMT referral simultaneously rather than sequentially, so evaluation for transplant is already underway if this course also relapses.
Not agreed, and stated directly rather than papered over: the gastroenterologist believes fidaxomicin has a genuine chance of breaking the cycle outright; the infectious disease physician expects it to buy time rather than resolve the underlying problem, and is treating this course as a bridge to FMT rather than an alternative to it. Both plans converge on the same next step regardless of who turns out to be right.