Clostridioides difficile (C. diff) is a spore-forming bacterium responsible for one of the most frequent healthcare-associated infections worldwide. It primarily targets the colon, or large intestine, where it proliferates and damages the intestinal lining. The infection is strongly associated with broad-spectrum antibiotics, which disrupt the gut’s normal bacterial balance, allowing C. diff to overgrow. While some individuals are colonized without symptoms, its presence often results in severe gastrointestinal distress.
The Standard Symptoms of C. diff Infection
The typical presentation of a C. diff infection involves gastrointestinal and systemic symptoms. The hallmark sign is severe, watery diarrhea, usually defined as three or more loose stools per day for at least two days. This frequent bowel activity results from the toxins the bacteria produce, causing inflammation and fluid secretion in the colon.
Patients commonly experience abdominal cramping and tenderness due to colon inflammation. Systemic signs like mild fever, loss of appetite, and nausea are also reported. Moderate infection causes significant fluid loss, leading to dehydration that may require medical intervention.
When C. diff Presents as Constipation
While C. diff is known for causing diarrhea, it can present as severe constipation, often signaling a more serious, complicated infection. This atypical presentation occurs because the powerful toxins produced by the bacteria, specifically Toxin A (an enterotoxin) and Toxin B (a cytotoxin), can induce a functional blockage in the colon. These toxins damage the cells lining the colon, leading to intense inflammation that interferes with the organ’s ability to move contents forward.
Paralytic Ileus
C. diff-related constipation can be caused by the development of paralytic ileus. This condition is not a physical obstruction but a paralysis of the intestinal muscles, stopping the normal rhythmic contractions, known as peristalsis. When the colon muscles cease to function, stool and gas cannot be propelled through the digestive tract. The resulting buildup causes painful abdominal distension.
Toxic Megacolon
Constipation in a patient with C. diff infection can signal toxic megacolon, a life-threatening complication. Toxic megacolon involves the rapid, non-obstructive dilation of the colon due to severe, full-thickness inflammation penetrating the colon wall. This inflammation paralyzes the colon, causing it to swell dramatically and halting all bowel movement and gas passage.
The patient may not exhibit diarrhea because the colon is too inflamed and distended to expel contents. The inability to pass stool or gas, combined with signs of systemic toxicity (fever, rapid heart rate, and low blood pressure), indicates a medical emergency. Constipation in a suspected or confirmed C. diff case warrants immediate medical evaluation.
Diagnosis and Treatment Overview
Confirmation of a C. diff infection requires laboratory testing, as symptoms alone are not sufficient for a definitive diagnosis. The standard approach involves testing a stool sample for the presence of the C. diff organism or its toxins (Toxin A and Toxin B). Nucleic acid amplification tests (NAAT) are frequently used to detect the bacterial DNA, while enzyme immunoassays (EIA) identify the toxins.
Management begins with supportive care, primarily focusing on hydration to replace fluids lost from diarrhea or to manage fluid imbalances in severe cases. If the infection was triggered by an antibiotic, that medication is typically stopped. The infection is then treated with specific antibiotics that target C. diff within the colon.
Oral vancomycin or fidaxomicin are the standard treatments, as they concentrate in the gut. Fidaxomicin is sometimes preferred due to a lower rate of recurrence compared to vancomycin. For patients with multiple recurrent infections, Fecal Microbiota Transplantation (FMT) may be considered. This procedure restores a healthy balance of gut flora by introducing screened donor stool into the patient’s colon.