A 67-yearold Chinese male was admitted for diarrhoea of 3 weeks, which was minimally bloody on one occasion and weight loss of 10 kg over 2 months. He was previously well and denied use of medications, recreational drugs or herbal preparations. He used to travel overseas frequently for social visits.
Clinical examination revealed wasting, blood pressure of 140/100 mmHg and temperature of 37.80C. There was no buccal pigmentation, oral thrush, tremor or goitre. There was mild tenderness in the left iliac fossa. Neurological examination was unremarkable.
His haemoglobin was 12.8 g/dl (normocytic), leucocytes 6.8x 103/ul, polymorphs 64%, lymphocytes 23.4%, eosinophils 2.6%. Serum sodium was 136 mmol/l, potassium 4.2 mmol/l, urea 4.6 mmol/l, random glucose 5.9 mmol/l, calcium 2.2 mmol/l (corrected). Thyroid function tests were normal. Chest radiograph (CXR) was unremarkable. Leucocytes were present in the stool. Blood and stool cultures did not yield any pathogens. A computed tomography of his abdomen was normal. He was treated empirically with intravenous ceftriaxone (2gm daily). A colonoscopy was considered in view of persistent diarrhoea.