Self-administration of metallic mercury by intravenous injection.

sigmoid regions and occasionally in the caecum. It results from pressure necrosis of the colonic wall from impacted faeces. Constipation is the pre-eminent symptom in all cases and straining at stool the precipitating event. Drug-induced faecal impaction is becoming more prevalent and is not uncommon in opiate addicts. Both faecal impaction and perforation have been recently reported in renal transplant patients in whom aluminium-based antacids have been implicated.2 In the present case constipation worsened during antidepressant therapy. Ayd3 reported that 60% of patients taking tricyclic antidepressants suffer from constipation, and cases ofadynamic ileus have been described in patients taking these drugs.4 Giving drugs that strongly inhibit colonic motility to patients with refractory constipation is not without hazard. Adequate resuscitation, antibiotic cover, and early operation form the basis of treatment. In generalised peritonitis exteriorisation5 with limited resection of the perforation and thorough peritoneal lavage remains the operation of choice. In contrast to similar situations in diverticular disease, mobilisation of the colon presents few problems. Advocates of resection and primary anastomosis must carefully consider the dangers of gross contamination and unprepared bowel in an often moribund patient. In localised infection or in right-sided perforations, however, this procedure becomes more feasible. Some surgeons delay primary closure of the skin incision in view of the unavoidable wound contamination. Antibiotic cover should be directed against Gram-negative and anaerobic organisms. Later, persisting constipation merits careful attention.