General

Common complications include:

• weight loss
• anaemia
• arthritis - large joints
• erythema nodosum
• ocular problems - conjunctivitis, episcleritis, iritis
• sacroiliitis - this is unrelated to HLA B27
• gall stones, especially of the cholesterol type

Less common:

• liver complications - primary sclerosing cholangitis, fatty liver, non-specific hepatitis, pericholangitis.
• ankylosing spondylitis - related to HLA B27
• pyoderma gangrenosum
• carcinoma of the bile ducts and primary sclerosing cholangitis - much less common than in ulcerative colitis
• renal complications - ureteric stricture, stones, right hydronephrosis, nephropathy (oxalate, amyloid).
• nutritional deficiency - osteomalacia, weakness (potassium, magnesium, vitamin D), lassitude (vitamin B12, folate, iron), rashes (zinc, niacin), alteration of taste (zinc).
• systemic amyloidosis - more common in Crohn's than UC
• reduced fertility

Reference:

1. Jewell, D. Crohn's disease. Medicine International 1994;22:8: 321-6.