Aetiology and pathogenesis of chronic diarrhoeal illness in adults

Abstract

Objective: Study the aetiology of chronic diarrhoea and understand the underlying pathology leading to the disease. Methodology: Chronic diarrhoea was defined as duration of diarrhoeal illness for approximately three weeks or longer. Nine fatal cases fulfilled the criterion and constituted the study population. Autopsy was carried out on all of them. Relevant clinical, laboratory and pathologic findings were demonstrated to understand the pathogenesis of the disease. Results: Intestinal amoebiasis, pancolitis with mucosal necrosis and variable degree of ulceration leading to serositis orcolonic perforations ranked top, being present in 3 (33.3%) cases. Coinfection with Shigella spp., malaria, and disseminated tuberculosis were found. Disseminated tuberculosis secondary to pulmonary tuberculosis with tuberculous ulcerations of the small bowel, or small bowel and ascending colon ranked second, being present in 2 (22.2%) cases. Severe cytomegalovirus (CMV)-associated ileitis and S/iigW/a-associated colitis were noted in these cases. Severe malnutrition was a common concomitant illness in all cases. Infections, suggestive of depressed cell-mediated immunity and/or pathologic findings of lymphoid atrophy, were present in 4 (44.4%) cases. One case with severe malnutrition and lymphoid atrophy had hyperinfection with Strongyloides stercoralis with evidence of auto-infection. Other rare causes included diabetes mellitus with pancytopenia and ileal ulcerations and shigellosis in one, combined congenital generalized lymphangiectasia with entire gastrointestinal (GI) tract involvement and secondary systemic amyloidosis with extensive GI tract involvement in one, and immuiiopiOiiferaiivc srna!! and large bowel disease in one. This postmortem study failed to enrol the cases of ulcerative colitis who got well with either medical or surgical management. Conclusion: Early management of potentially treatable infectious diseases leading to chronic diarrhoeal illness and concurrent nutritional support should be tried. Strongyloidiasis in malnourished patients should be treated.