An Unusual Cause of Diarrhea and Hematochezia

In November 2024, our team first reported on the use of washed microbiota transplantation (WMT) to cure Bevacizumab-induced colitis in the international leading journal Endoscopy.

A 71-year-old man was referred to our hospital because of a 1-week history of hematochezia and severe diarrhea occurring 10 times per day. The patient also reported fatigue, decreased appetite and abdominal pain. He had a history of colon cancer, diagnosed 10 months ago and subsequently underwent a left hemicolectomy. He had been undergoing treatment with oxaliplatin and capecitabine for 7 months, but was switched to the therapy of Bevacizumab combined with calcium folinate and fluorouracil a week ago due to multiple liver metastases. After the first course, he developed abdominal pain, hematochezia and diarrhea, with mucous and watery stool. There was no recent consumption of raw or undercooked foods, and he had not experienced a fever, nausea, or vomiting. No history of hypertension or diabetes, and denied having taken antibiotics or nonsteroidal anti-inflammatory drugs. Marked elevated levels of C-reactive protein (44.14 mg/L, reference range 0-10 mg/L) and white blood cell count (15.38×10 9 /L, reference range 4-10×10 9 /L) were observed, while other laboratory tests were normal. He tested negative for infection with tuberculosis, HIV, EpsteinBarr virus, and cytomegalovirus. Blood cultures and tests for Clostridioides difficile (CD) were also negative. An abdominal computed tomography (CT) scan showed thickening of the left-side colon wall with surrounding exudate, while the ascending and transverse colon walls appeared normal. The artery computed tomography angiography (CTA) was conducted as well. Colonoscopy revealed scattered erythema, congestion and full circumferential edema of the total colon, with multiple extensive erosions and deep ulcers in the mucosa located 10-40 cm away from the anus. After ruling out other causes of colitis, such as infection or ischemic factors, a diagnosis of Bevacizumab-induced colitis was established. The patient underwent four times of WMT, without the use of corticosteroids, immunosuppressants and biological agents. One month after treatment, the patient’s abdominal pain, hematochezia and diarrhea gradually disappeared. At a 3-month follow up, he demonstrated a full resolution of the symptoms previously experienced. The abdominal CT scan revealed an improvement in the thickening of left-side colon wall. Colonoscopy showed significant healing of extensive erosions and deep large ulcers. At a 18-month follow-up, he remained free from these gastrointestinal symptoms. This is the first report that WMT successfully cured Bevacizumab-induced colitis. The present findings indicated the new option for managing of Bevacizumab-induced colitis using microbiome-based treatment.

Reference: Chen S, Wen Q, Zhang F. An Unusual Cause of Diarrhea and Hematochezia. Gastroenterology. 2024 Nov 22:S0016-5085(24)05742-1. doi: 10.1053/j.gastro.2024.11.007. Epub ahead of print. PMID: 39581509.

First Author: Siyu Chen

Corresponding author：Faming Zhang