An 18-year-old male presents with fever, abdominal pain, and diarrhea (10+ times/day) for 2 days. Initially loose stools progressed to mucopurulent bloody stools with tenesmus. Stool exam shows WBC 15-20/HPF and RBC 5-10/HPF. After 3 days of antibiotic therapy, symptoms improved but treatment was discontinued prematurely. What is the likely consequence?