What is the best treatment approach for a patient with ulcerative colitis (UC) presenting with bloody diarrhea?

Treatment of Ulcerative Colitis with Bloody Diarrhea

For ulcerative colitis presenting with bloody diarrhea, immediately classify disease severity using Truelove and Witts' criteria to determine if the patient has mild-moderate distal disease (requiring topical plus oral mesalamine) versus severe disease (requiring immediate IV corticosteroids with joint gastroenterology-surgery management). 1

Initial Severity Assessment

The first critical step is determining disease severity, as this dictates the entire treatment pathway:

Severe UC is defined by: bloody stool frequency ≥6/day PLUS at least one of the following: heart rate >90/min, temperature >37.8°C, hemoglobin <10.5 g/dL, or ESR >30 mm/h (CRP >30 mg/L can substitute) 1

• Patients meeting these criteria require immediate hospital admission for intensive IV therapy without delay 2, 1
• Do not wait for stool culture results before initiating corticosteroid treatment, even though acute onset UC can be difficult to distinguish from infectious colitis 2, 1

Treatment Algorithm by Disease Severity

Mild to Moderate Distal UC (Proctitis or Left-Sided Disease)

First-line therapy: Combination of topical mesalamine 1g daily PLUS oral mesalamine 2-4g daily 1

• This combination is more effective than either agent alone 2
• For proctitis specifically, mesalamine 1g suppository once daily is first-line 1
• Topical corticosteroids are less effective than topical mesalamine and should be reserved as second-line for patients intolerant of topical mesalamine 2

If no improvement on combination therapy: Escalate to oral prednisolone 40mg daily with continued topical agents as adjunctive therapy 2, 1

• Taper prednisolone gradually over 8 weeks according to severity and patient response 2

Severe UC Requiring Hospitalization

Immediate management upon admission:

• Start IV hydrocortisone 100mg four times daily OR methylprednisolone 40-60mg daily immediately 1
• Establish joint care with gastroenterologist AND colorectal surgeon from admission 1
• Inform patient of 25-30% chance of needing colectomy 2, 1

Intensive monitoring protocol:

• Physical examination daily for abdominal tenderness and rebound 2
• Vital signs four times daily 2
• Stool chart documenting frequency, character, and presence of blood 2
• FBC, ESR/CRP, electrolytes, albumin, and liver function every 24-48 hours 2
• Daily abdominal radiography if colonic dilatation (transverse colon >5.5cm) detected at presentation 2

Supportive care:

• IV fluid and electrolyte replacement to correct dehydration 2
• Blood transfusion to maintain hemoglobin >10 g/dL 2
• Subcutaneous heparin to reduce thromboembolism risk 2
• Nutritional support (enteral or parenteral) if malnourished 2

Rescue Therapy for Steroid-Refractory Disease

If no response to IV corticosteroids after 3-5 days: Two equally effective rescue options exist 1

• Infliximab 5mg/kg IV 1, 3
• Cyclosporine 2mg/kg IV 1

Critical timing: Limit IV corticosteroid duration to 7-10 days maximum, as extending beyond this carries no additional benefit and delays definitive therapy 1

• Overall response rate to IV corticosteroids is 67%, with 33% requiring colectomy 1
• Do not extend IV corticosteroids beyond 7-10 days without escalating to rescue therapy or surgery 1

Surgical Indications

Absolute Emergency Indications (Immediate Surgery)

• Free perforation with generalized peritonitis 1
• Life-threatening hemorrhage with hemodynamic instability despite resuscitation 1
• Toxic megacolon complicated by perforation, massive bleeding, clinical deterioration, or signs of shock 4, 1

Mandatory Surgery Within 24-48 Hours

Toxic megacolon with no clinical improvement after 24-48 hours of medical treatment requires mandatory surgery 4, 1

• Surgery should not be delayed beyond 48-72 hours from diagnosis if no clinical improvement, as prolonged observation increases perforation risk and mortality 4
• The most critical error is delaying surgery while attempting additional medical therapy in a patient who has already failed medical treatment and has toxic megacolon, which substantially increases mortality 4

Surgical procedure of choice: Subtotal colectomy with end ileostomy 4, 1

Maintenance Therapy After Remission Induction

Lifelong maintenance therapy is recommended for all patients, particularly those with left-sided or extensive disease 2, 1

• Continue with the agent successful in achieving induction, except corticosteroids 1
• For moderate-to-severe disease requiring biologics, options include infliximab, adalimumab, vedolizumab, ustekinumab, or tofacitinib 1
• Maintenance therapy reduces the risk of colorectal cancer 2

Critical Pitfalls to Avoid

• Never delay corticosteroid treatment while waiting for stool microbiology results in suspected severe UC 1
• Never delay surgery in critically ill patients with toxic megacolon, as this increases perforation risk with high mortality 1
• Never extend IV corticosteroids beyond 7-10 days without escalating to rescue therapy or surgery 1
• Never manage severe UC without early surgical consultation, as delayed surgery is associated with high morbidity 1