Case presentation A 70-year-old man with insulin-dependent diabetes and hypertension, with negative
serologies for hepatitis and HIV, has a history of a prostate abscess in 2020 that
evolved into a rectal fistula, requiring intestinal diversion. In 2024, he underwent
a reconstruction surgery with transverse ileal anastomosis, through a specific incision,
with antibiotic prophylaxis (ceftriaxone and metronidazole). Ten days post-surgery,
he developed abdominal pain, watery diarrhea, fever, and loss of appetite. Abdominal
and pelvic CT showed pneumoperitoneum and diffuse distension of the intestinal loops,
with no clinical signs of peritonitis. Treatment with metronidazole was started, suspected
as nonspecific colitis, and a test for Clostridium was collected. After a positive
result for Clostridium, treatment with oral vancomycin was initiated for 14 days,
resulting in clinical and laboratory improvement. Sixty days after discharge, symptoms
of diarrhea and abdominal pain reappeared, with another positive culture for Clostridium.
Oral vancomycin treatment was restarted for 42 days in a tapering regimen. The patient
returned to the outpatient clinic 20 days after completing treatment, asymptomatic.
Discussion Although almost always related to antibiotic use, 30% of cases are associated with
other risk factors, such as advanced age, hospitalization, and severe underlying conditions.
For recurrent infection, risk factors include age > 65 years, severe underlying medical
conditions, ongoing antibiotic therapy during treatment for pseudomembranous colitis,
serum creatinine ≥1.2 mg/dL, and lack of immune response mediated by antibodies to
C. difficile toxins, especially toxin B. Recurring episodes, which occur in 35% of
cases, are defined by symptom resolution during therapy and recurrence within 2 months.
The approach is the same, using fidaxomicin, vancomycin, or metronidazole. In these
cases, 50 to 60% may develop a new recurrence.
Conclusion Pseudomembranous colitis is a rare diagnosis, particularly in immunocompetent patients
without prior antibiotic therapy.
