European Journal of Biomedical and Pharmaceutical Sciences

A COLON UNDER SIEGE: PERSISTENT BLOODY DIARRHEA FOLLOWING PROLONGED BROAD-SPECTRUM ANTIBIOTIC EXPOSURE – A CASE REPORT

G. Rathnakumar, A. Ravi*, R. Chandraganesan, H Ansar Fathima, N. Dhanushya

ABSTRACT

Chronic diarrhea with blood and mucus represents a significant diagnostic challenge, particularly in patients with prolonged hospitalization and exposure to multiple antibiotics. Antibiotic-associated colitis is an important cause of persistent diarrhea and may present with severe systemic manifestations if not recognized early. We report the case of a 44-year-old female who presented with persistent loose stools for two months, occurring 12–14 episodes per day, which were blood-stained, mucoid, and small in volume. The diarrhea was associated with diffuse lower abdominal cramping relieved after defecation, tenesmus, fecal incontinence, nocturnal stools, weight loss, and loss of appetite. The patient also complained of recurrent vomiting for the same duration. Her medical history was significant for systemic hypertension for seven years on treatment, coronary artery disease on antiplatelet therapy, and chronic steroid use for suspected inflammatory arthritis. Three months prior to presentation, the patient had sustained a pin-prick injury to the right foot, which progressed to abscess formation and severe cellulitis requiring multiple hospital admissions, incision and drainage, fasciotomy, and split skin grafting. During this period she received several broad-spectrum intravenous antibiotics including meropenem, piperacillin- tazobactam, cefoperazone-sulbactam, fosfomycin, nitrofurantoin, and linezolid. Notably, the onset of diarrhea occurred approximately 20 days after fasciotomy and prolonged antibiotic therapy. On examination, the patient appeared poorly nourished and dehydrated with pallor, glossitis, and angular stomatitis, along with bilateral pedal edema. Local examination of the right lower limb revealed healing fasciotomy wound with healthy granulation tissue. Laboratory investigations demonstrated severe anemia (Hemoglobin 6.1–7.7 g/dL), elevated inflammatory markers (ESR 120 mm/hr, CRP 69 mg/L), hypokalemia, and hypoalbuminemia. Peripheral smear findings were suggestive of dimorphic anemia. Stool examination revealed occult blood positivity with no ova or cysts detected. Ultrasonography of the abdomen showed moderate hepatosplenomegaly, grade II fatty liver, and cholelithiasis. The clinical presentation, along with the temporal relationship to prolonged antibiotic exposure, raised suspicion of antibiotic-associated colitis, with differentials including pseudomembranous colitis and inflammatory bowel disease. This case highlights the importance of recognizing persistent diarrhea following extensive antibiotic exposure and emphasizes the need for early diagnostic evaluation to prevent complications. Timely identification and targeted management remain crucial in improving patient outcomes.

Keywords: Antibiotic-Associated Colitis, Chronic Bloody Diarrhea, Broad-Spectrum Antibiotics, Pseudomembranous Colitis.