Severe strongyloidiasis presenting as occult gastro-intestinal tract malignancy

A 38-year-old man presented with severe loss of weight, diarrhoea alternating with constipation and blood in the stool. Clinically, colonic malignancy was suspected, but this was not confirmed. Fresh stool contained numerous larvae of Strongyloides stercoralis. The patient responded promptly to levamisole, with cessation of symptoms and rapid weight gain.