A 68-year-old man comes to the office due to diarrhea. He was recently diagnosed with cecal adenocarcinoma and underwent right-sided hemicolectomy and regional lymph node removal 2 months ago. The postoperative course was uncomplicated, and the patient received his first cycle of adjuvant chemotherapy 3 weeks ago. Afterward, he had mild nausea that resolved with antiemetics. Two days ago, worsening lower abdominal cramps and watery diarrhea began. The patient has consumed nothing out of the ordinary, has no ill contacts, and has not recently used antibiotics. Temperature is 37.9 C (100.2 F), blood pressure is 118/70 mm Hg, and pulse is 92/min. Physical examination shows moist mucous membranes. The abdomen is soft with mild, generalized tenderness and increased bowel sounds. The surgical wound from 2 months ago is well healed. Testing for stool occult blood is negative, and other laboratory results are as follows:
| Hemoglobin | 11.8 g/dL |
| Platelets | 140,000/mm3 |
| Leukocytes | 14,000/mm3 |
| Total bilirubin | 0.8 mg/dL |
| Alkaline phosphatase | 70 U/L |
| Aspartate aminotransferase (SGOT) | 18 U/L |
| Alanine aminotransferase (SGPT) | 24 U/L |
Abdominal x-ray reveals nondilated bowel. Which of the following is the best next step in management of this patient?
| Clostridioides difficile colitis | |
Risk factors |
|
Clinical |
|
Diagnosis |
|
Infection |
|
*Genes specific to toxigenic strains are assessed. EIA = enzyme immunoassay; H2 = histamine-2 receptor; PPI = proton pump inhibitor. | |
This patient, who recently received chemotherapy and has developed watery diarrhea, lower abdominal cramps, low-grade fever, and leukocytosis, should be evaluated for Clostridioides difficile infection (CDI). Although recent antibiotic use is the strongest risk factor, cytotoxic chemotherapy can also predispose to CDI because it directly damages the intestinal epithelium and has antimicrobial, as well as immunosuppressive, properties. Other risk factors include recent hospitalization and advanced age (>65).
CDI typically manifests with watery diarrhea (≥3 episodes in 24 hr), abdominal cramps, nausea, fever, and leukocytosis. It is diagnosed with stool testing. Stool PCR assesses for genes specific to toxigenic C difficile strains. PCR can be performed rapidly and is highly sensitive, although it is less specific for active infection (vs carrier status) than enzyme immunoassay for C difficile toxins, which detects active toxin production. When patients, such as this one, already have symptoms of active infection (ie, excluding asymptomatic carrier status), PCR is usually diagnostic.
(Choice A) Chemotherapy-induced diarrhea is common and results from cytotoxic damage to the gastrointestinal epithelium; it is often managed with antidiarrheal medications (eg, loperamide) and rehydration. However, this is a diagnosis of exclusion; this patient's elevated leukocyte count of 14,000/mm3 and temperature of 37.9 C (100.2 F) shoudl raise suspicion for CDI and require further evaluation.
(Choice B) Carbohydrate breath testing can be used to diagnose small intestinal bacterial overgrowth, which can occur after bowel resection and typically presents with postprandial diarrhea and bloating. However, leukocytosis and fever would be unexpected.
(Choice C) Ganciclovir is used to treat cytomegalovirus colitis, which can cause fever, leukocytosis, abdominal pain, and diarrhea (watery or sometimes bloody). Although it can occur in patients undergoing chemotherapy, it is more common in patients who have AIDS or who have had organ transplants. In addition, the diagnosis requires biopsy and culture; empiric treatment is not recommended due to drug toxicity.
(Choice E) T-lymphocyte–directed immunosuppressants (eg, cyclosporine, tacrolimus) are used in the treatment of graft versus host disease, which can cause diarrhea and abdominal pain. However, this disease occurs as a complication of allogenic hematopoietic stem cell transplant, not chemotherapy for a solid organ malignancy.
Educational objective:
Clostridioides difficile infection presents with watery diarrhea, abdominal cramps, nausea, fever, and leukocytosis. Risk factors include antibiotic use, cytotoxic chemotherapy, recent hospitalizations, and advanced age. Stool PCR is usually diagnostic.