What is the greatest risk for a patient with a severe flare-up of ulcerative colitis (UC) presenting with generalized abdominal pain, cramping, hyperactive bowel sounds, and bright red blood in stool, with elevated leukocyte count and normal vital signs?

Venous Thromboembolism is the Greatest Risk for a Patient with Severe Ulcerative Colitis Flare-Up

The patient with acute ulcerative colitis flare-up is at greatest risk for venous thromboembolism (VTE). 1

Clinical Presentation Analysis

This 39-year-old man presents with:

• 8-day history of worsening generalized abdominal pain and cramping
• 6 episodes of diarrhea daily with bright red blood
• No fever or chills
• Normal vital signs
• Generalized abdominal tenderness without rebound or rigidity
• Hyperactive bowel sounds
• Leukocytosis (13,000)
• Hypokalemia (3.3)
• No bowel obstruction on abdominal radiograph

Risk Assessment for Each Option

Venous Thromboembolism

• Patients with acute severe ulcerative colitis are at significantly increased risk for thromboembolism 1
• The British Society of Gastroenterology guidelines specifically recommend low molecular weight heparin prophylaxis as part of standard management for acute severe UC 1
• The inflammatory state of UC creates a hypercoagulable condition
• Immobility during hospitalization further increases this risk

Toxic Megacolon

• Defined as radiological signs of distension of the colon (≥5.5 cm) combined with signs of severe systemic inflammatory response 1
• Current presentation lacks:
  • Fever (patient has no fever or chills)
  • Colonic distension (abdominal radiograph shows no obstruction)
  • Severe systemic toxicity
  • Decreased bowel sounds (patient has hyperactive bowel sounds)

Bowel Perforation

• Most serious complication of acute severe colitis 1
• Usually associated with toxic megacolon or inappropriate colonoscopy
• Patient lacks peritoneal signs (no rebound or rigidity)
• No evidence of severe systemic toxicity
• Abdominal radiograph shows no obstruction or distension

Pericarditis

• Not a common complication of ulcerative colitis flare-ups
• No evidence of chest pain or other cardiac symptoms in this case

Management Approach

1. Immediate VTE prophylaxis

   • Initiate low molecular weight heparin prophylaxis 1

2. Continue current treatment

   • Continue intravenous methylprednisolone and IV fluids
   • Correct hypokalemia (3.3)
   • Monitor stool frequency, consistency, and blood

3. Daily monitoring

   • Daily assessment of:
     • Vital signs
     • Abdominal examination
     • Stool charts (frequency, consistency, blood)
     • Laboratory values (CBC, electrolytes, CRP, albumin) 1

4. Assess response to steroids by day 3

   • If >8 stools/day OR 3-8 stools/day with CRP >45 mg/L, consider rescue therapy 1
   • Options include infliximab or cyclosporine if no contraindications

5. Surgical consultation

   • Obtain early surgical consultation if patient develops:
     • Worsening abdominal pain
     • Signs of peritonitis
     • Fever
     • Radiological evidence of colonic distension

Warning Signs to Monitor

• Development of fever
• Increasing abdominal pain or distension
• Development of peritoneal signs
• Increasing stool frequency
• Radiological evidence of colonic distension
• Worsening systemic toxicity

While toxic megacolon, bowel perforation, and pericarditis are potential complications of severe ulcerative colitis, the clinical presentation and current evidence indicate that venous thromboembolism represents the most immediate risk for this patient based on the guidelines and the patient's clinical status.