Recurrent meningitis in a child with combined IgA deficiency and splenic hypoplasia.

The sampling tube, an open-ended polyethylene feeding catheter sterilised by the manufacturer, is filled with sterile distilled water. A 2.0% suspension of agar in distilled water is prepared and enough cochineal to colour the solution is added. This is autoclaved at 44N/10 min to dissolve and sterilise the agar. When the solution has cooled to 60°C an 8 cm length of the coloured agar solution is aspirated into the distal end of the tube. The colouring reagent helps when filling the tube. The tube is left for an hour at room temperature for the agar to gel and it can then be passed into the duodenum where its position is confirmed radiographically. The agar plug is then expelled by flushing the tube through with sterile distilled water using hydraulic pressure to dislodge the plug. This technique has been successfully used by us on many occasions to obtain samples of small intestinal juice for microbiological study from patients with gastrointestinal disorders.