What are the common symptoms and treatment options for a patient suspected of having Crohn's disease?

Crohn's Disease: Symptoms and Treatment

Common Symptoms

Crohn's disease typically presents with chronic diarrhea (lasting >6 weeks), abdominal pain, weight loss, and fever—symptoms that distinguish it from other gastrointestinal conditions. 1, 2

Gastrointestinal Manifestations

• Diarrhea is the hallmark symptom, with severe flares producing at least 10 loose stools daily, though milder disease may present with fewer bowel movements 3, 2
• Abdominal pain occurs daily during moderate to severe flares, typically colicky in nature reflecting active intestinal inflammation 3
• Weight loss develops from both malabsorption and reduced oral intake, serving as a key indicator of disease severity 3, 4
• Rectal bleeding may occur, though less prominent than in ulcerative colitis 5

Systemic Symptoms

• Fever is more common in Crohn's flares than ulcerative colitis and helps distinguish between the two conditions 3, 6
• Malaise, anorexia, and fatigue are systemic features that differentiate Crohn's exacerbations from other inflammatory bowel conditions 3, 5
• Failure to thrive, growth impairment, and delayed puberty may occur in pediatric patients 4

Extraintestinal Manifestations

• Arthritis (inflammatory arthropathies) affects nearly half of patients 4, 6
• Ocular complications including uveitis, episcleritis, and scleritis 4, 6, 7
• Dermatologic manifestations such as erythema nodosum, pyoderma gangrenosum, and aphthous stomatitis 4, 6, 7
• Osteoporosis, nephrolithiasis, and cholelithiasis represent additional systemic complications 6

Diagnostic Approach

Ileocolonoscopy with segmental biopsies should be performed when Crohn's disease is suspected and the procedure is clinically safe, as it allows assessment of disease extent and histological confirmation. 1, 2

Initial Evaluation

• Fecal calprotectin is a reliable screening tool; levels >100 mg/g predict positive findings (43%), with >200 mg/g providing even higher diagnostic yield (65%) 2, 5
• Laboratory assessment should include C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), complete blood count, albumin, and nutritional markers (vitamin B12, folate, vitamin D) 3, 6, 5
• Elevated CRP reflects inflammatory burden during active disease 3
• Low serum albumin indicates both inflammation and poor nutritional status 3

Endoscopic Evaluation

• Ileocolonoscopy with biopsies remains first-line investigation, using standardized endoscopic scoring systems to define severity 1, 2
• Discontinuous "skip lesions" are characteristic of Crohn's disease, unlike the continuous inflammation of ulcerative colitis 7
• Transmural inflammation often involves the ileocecal region and may lead to stricturing or fistulizing phenotypes 4

Cross-Sectional Imaging

• MR enterography (MRE) is preferred as first-line imaging because it does not expose patients to ionizing radiation and has similar diagnostic accuracy to CT enterography 1, 2
• CT enterography is appropriate when MRI is unavailable or in emergency settings 2
• Intestinal ultrasound (IUS) may be used depending on local availability and expertise 1

Advanced Diagnostic Modalities

• Capsule endoscopy should be performed when small bowel Crohn's disease is suspected despite normal or inconclusive ileocolonoscopy and imaging studies 1, 2
• Patency capsule should be used prior to capsule endoscopy in patients with obstructive symptoms, history of small bowel resection, or known stenosis to reduce retention risk (3.6% in suspected disease vs 8.2% in established disease) 1, 2
• Balloon-assisted enteroscopy is reserved for patients with high clinical suspicion despite negative tests, or when therapeutic intervention (stricture dilatation) is needed 1

Treatment Options

Mild to Moderate Ileocecal Disease

Ileal-release budesonide 9 mg once daily for 8 weeks is the recommended first-line treatment for mild to moderate ileocecal Crohn's disease, with efficacy of 51% and significantly fewer side effects than systemic corticosteroids. 1

• Budesonide 9 mg once daily for 8 weeks induces remission as effectively as prednisolone (40 mg tapering) but with fewer adverse effects 1
• Taper budesonide over 1-2 weeks once remission is achieved 1
• Budesonide is inferior to prednisolone in severe disease (CDAI >300) 1

Mild to Moderate Colonic Disease

• Systemic corticosteroids (prednisolone 40 mg tapering by 5 mg weekly) are effective for colonic Crohn's disease, tailored to disease severity 1
• Sulfasalazine is a reasonable choice for colonic disease, though other aminosalicylates have no proven role 8
• Ileal-release budesonide has benefit in proximal colonic disease but not distal colonic inflammation 1

Moderate to Severe Disease

Patients with moderate to severe Crohn's disease (CDAI 220-450 for moderate; >450 for severe) should receive biologics, with or without immunomodulators, to induce and maintain remission. 3, 5

Anti-TNF Therapy

• Infliximab 5 mg/kg IV at weeks 0,2, and 6, then every 8 weeks for maintenance 9

  • For patients who lose response, consider increasing to 10 mg/kg 9
  • Discontinue if no response by week 14 9
  • Warning: Increased risk of serious infections (tuberculosis, invasive fungal infections) and malignancy, including hepatosplenic T-cell lymphoma in adolescents/young adults on concomitant azathioprine/6-mercaptopurine 9

• Adalimumab: Adults receive 160 mg day 1,80 mg day 15, then 40 mg every other week starting day 29 10

  • Pediatric dosing (≥6 years): Weight-based from 20 mg to 40 mg every other week 10
  • Warning: Same serious infection and malignancy risks as infliximab 10

Immunomodulators

• Azathioprine or 6-mercaptopurine may be used for maintenance therapy in select patients with mild-to-moderate disease 8
• Methotrexate is often used concomitantly with anti-TNF agents 9
• Withdrawal of purine analogues or anti-TNF therapy (monotherapy or combination) is associated with significant relapse risk; shared decision-making is essential 1

Fistulizing Disease

• Infliximab is indicated for reducing the number of draining enterocutaneous and rectovaginal fistulas and maintaining fistula closure 9
• Setons should be placed to prevent sepsis in fistulizing perianal Crohn's disease 1
• Pelvic MRI and examination under anesthesia by an experienced colorectal surgeon are essential for assessment 1

Pediatric Considerations

• Infliximab or adalimumab are indicated for pediatric patients ≥6 years with moderately to severely active disease who have failed conventional therapy 9, 10
• Enteral nutrition is an option for induction therapy in children 5

Obstructive Symptoms

• Endoscopic dilatation is preferred over surgery for symptomatic strictures <4 cm to avoid prolonged hospitalization and recovery 1
• Conservative management includes nasogastric decompression, bowel rest, IV fluids, and electrolyte replacement 1

Disease Monitoring

A multimodal approach to monitoring remission is advised, including clinical assessment, biochemical markers (CRP, fecal calprotectin), cross-sectional imaging, and endoscopy with histology. 1

Objective Measures

• Crohn's Disease Activity Index (CDAI) provides objective severity assessment: remission <150, mild 150-220, moderate 220-450, severe >450 3
• Harvey-Bradshaw Index (HBI) offers simpler clinical assessment using general well-being, abdominal pain, liquid stool frequency, abdominal mass, and extraintestinal manifestations 3
• Fecal calprotectin should be used to monitor disease in patients with known location and baseline value 1
• Endoscopic remission (absence of ulcerations) predicts better long-term outcomes than symptomatic improvement alone 3

Common Pitfalls

• Symptoms and inflammation can be disconnected—inflammation often persists without gastrointestinal symptoms and may lead to progressive bowel damage 2
• Do not delay surveillance >3 months in high-risk patients (primary sclerosing cholangitis, prior dysplasia) due to colorectal cancer risk 1
• Test for latent tuberculosis before initiating anti-TNF therapy and monitor during treatment, even if initial test is negative 9, 10