Kolitis

Kolitis, or colitis, is inflammation of the lining of the colon (large intestine). It can be acute or chronic and results from infection, inflammatory bowel disease, ischemia, microscopic colitis, medications, or radiation. The condition commonly causes diarrhea and abdominal pain, sometimes with blood or mucus in the stool.

Symptoms typically include diarrhea (which may be watery or bloody), abdominal cramps, urgency, and sometimes fever, weight loss, or fatigue. The pattern varies with the cause; infectious colitis often has a sudden onset, while inflammatory colitis tends to produce ongoing symptoms.

Causes and types include infectious colitis from bacteria, viruses, or parasites, and antibiotic-associated colitis due to Clostridioides difficile. Inflammatory colitis comprises ulcerative colitis and Crohn's disease with colitis. Ischemic colitis results from reduced blood flow, usually in older adults. Microscopic colitis causes chronic watery diarrhea. Other forms include medication-induced colitis, radiation colitis, and eosinophilic colitis.

Diagnosis is based on medical history and examination, stool tests for pathogens and toxins, and blood tests for inflammation or anemia. Colonoscopy with biopsies is commonly performed, and imaging such as CT or ultrasound may assess complications or alternative explanations.

Treatment depends on the cause. Supportive care with fluids and electrolyte management, plus dietary adjustments, is common. Infectious colitis requires targeted antimicrobials; C. difficile infection requires specific therapy (often vancomycin or fidaxomicin). Inflammatory colitis may require 5-ASA drugs, corticosteroids, immunomodulators, or biologics; ischemic or radiation colitis is treated by addressing the underlying issue. Severe disease may necessitate surgery.

Prognosis varies; some forms resolve, others are chronic. Long-standing ulcerative colitis or Crohn's disease with colitis increases colorectal cancer risk, making regular medical follow-up important. Prevention focuses on treating underlying causes promptly and avoiding known triggers when possible.