What is the treatment approach for an adult patient with no significant medical history presenting with a rectal ulcer?

Treatment of Rectal Ulcer

The treatment approach for a rectal ulcer in an adult with no significant medical history depends critically on the underlying etiology, which must be determined through clinical evaluation, sigmoidoscopy with biopsy, and exclusion of inflammatory bowel disease (IBD), infection, malignancy, and solitary rectal ulcer syndrome (SRUS).

Initial Diagnostic Evaluation

Before initiating treatment, establish the diagnosis through:

• Complete history focusing on: rectal bleeding pattern, mucorrhea, straining during defecation, tenesmus, incomplete evacuation sensation, constipation, recent travel, medications, smoking status, and family history of IBD 1, 2
• Physical examination including: digital rectal examination to assess for masses, tenderness, ulcer location, and perianal disease 1
• Laboratory investigations: complete blood count, inflammatory markers (ESR or CRP), serum albumin, liver function tests, and stool cultures including Clostridium difficile toxin to exclude infectious causes 1
• Sigmoidoscopy or colonoscopy: essential for visualizing the ulcer, assessing extent and pattern of inflammation, and obtaining biopsies for histopathology 1
• Rectal biopsy: the definitive diagnostic method to distinguish between IBD-related ulceration, SRUS (characterized by fibromuscular obliteration of lamina propria), malignancy, and other causes 2, 3

Treatment Algorithm Based on Etiology

If Ulcerative Colitis is Diagnosed

The treatment depends on disease extent and severity:

For distal/proctitis disease:

• First-line: Topical mesalamine (5-ASA) combined with oral mesalamine for optimal efficacy 1, 4
• Dosing: Oral mesalamine 2.4-4.8 g daily has demonstrated 29-41% remission rates at 8 weeks versus 13-22% with placebo 4
• Alternative: Topical corticosteroids if mesalamine fails or is not tolerated 1

For more extensive or moderate disease:

• Combination therapy: Oral mesalamine 4 g daily plus topical mesalamine, with addition of oral prednisolone 40 mg daily if inadequate response 1
• Steroid taper: Reduce prednisolone gradually over 8 weeks to prevent early relapse 1

For severe disease requiring hospitalization:

• Intravenous corticosteroids: Hydrocortisone 400 mg/day or methylprednisolone 60 mg/day 1
• Supportive care: IV fluid/electrolyte replacement, blood transfusion to maintain hemoglobin >10 g/dL, subcutaneous heparin for thromboembolism prophylaxis 1
• Joint medical-surgical management: Daily monitoring with vital signs, stool charts, laboratory tests every 24-48 hours, and daily abdominal radiography if colonic dilatation present 1
• Escalation if refractory: Consider calcineurin inhibitors (cyclosporine, tacrolimus) or anti-TNF biologics (infliximab) 5
• Surgical consultation: Patients should be informed of 25-30% colectomy risk 1

If Crohn's Disease is Diagnosed

For mild to moderate ileocolonic/colonic disease:

• Initial therapy: High-dose mesalazine 4 g daily 1
• Step-up: Oral prednisolone 40 mg daily if mesalazine fails, tapered over 8 weeks 1
• Alternative: Budesonide 9 mg daily for isolated ileocecal disease (marginally less effective than prednisolone) 1

For severe disease:

• IV corticosteroids: Hydrocortisone 400 mg/day or methylprednisolone 60 mg/day 1
• Concomitant IV metronidazole: Often advisable as distinguishing active disease from septic complications can be difficult 1

If Solitary Rectal Ulcer Syndrome (SRUS) is Diagnosed

Conservative management (first-line):

• Behavioral modifications: Avoid straining, establish regular toilet habits 2
• Bulk laxatives: To reduce straining during defecation 2
• Topical sucralfate enemas: 2 g twice daily for 6 weeks has shown complete symptom relief in 67% and marked improvement in 33% of patients, with macroscopic healing in all treated cases 6
• Alternative topical therapy: Steroid enemas 2
• Biofeedback therapy: For paradoxical puborectalis contraction 2

Surgical intervention: Reserved for refractory cases after conservative management fails 3

If Dieulafoy's Ulcer is Suspected

This rare cause presents with massive rectal bleeding:

• Diagnosis: Rigid sigmoidoscopy to visualize the lesion 7
• Treatment: Widely oversewing the vessel as primary therapy, as endoscopic coagulation has high failure rates for rectal lesions 7
• Resection: Reserved for cases failing primary surgical repair 7

Critical Pitfalls to Avoid

• Do not delay treatment waiting for stool microbiology results if severe colitis is suspected 1
• Do not miss IBD: SRUS may be misdiagnosed as anal fissure or juvenile polyp; maintain high index of suspicion and obtain biopsy 2
• Do not assume all rectal ulcers are benign: Exclude malignancy, tuberculosis, Behçet's disease, lymphoma, and vasculitis through appropriate histopathology 1
• Do not perform colonoscopy in severe disease: Flexible sigmoidoscopy is safer due to perforation risk; defer full colonoscopy until clinical improvement 1
• Monitor for complications: In severe UC, check for colonic dilatation (transverse colon >5.5 cm), toxic megacolon, perforation, and severe bleeding requiring emergency surgery 5

Maintenance Therapy

Once remission is achieved in IBD:

• Lifelong maintenance recommended: Particularly for left-sided or extensive UC, and distal disease with >1 relapse/year 1
• Options: Aminosalicylates, azathioprine, or mercaptopurine to reduce relapse risk and potentially colorectal cancer risk 1
• Mesalamine maintenance: 2.4 g once daily maintains remission in 84% at 6 months 4