Colonic polyps: a rare clinical manifestation of schistosomiasis (a case report)

Schistosomiasis is caused by parasitic blood flukes. It is one of the neglected tropical diseases (NTDs) and has variable manifestations depending on the species involved. Eggs and not adult worms are mostly responsible for the resultant pathologies commonly involving the small intestines. Colon polyps resulting from schistosomiasis represent a rare entity despite the endemicity of Schistosoma mansoni in the tropical regions. Praziquantel is the mainstay of treatment. Case presentation is of a 28 year old male with complaints of bloating, mild abdominal pain and loose stools over two weeks.On examination, the patient´s abdomen was soft on palpation with a liver span of 8 cm and a non-palpable spleen. Preliminary tests included stool microscopy which was negative for ova and cysts, negative for stool H. pylori antigen. Colonoscopy revealed a polyp at the caecum and pan-colonic erosions. Microscopy of the polyp showed numerous schistosome ova. The indolent picture of this particular patient makes it a unique case as the likelihood of the diagnosis not being schistosomiasis is greater than other differential diagnoses. The take-home message is that a high index of suspicion is needed in the diagnosis of colonic polyps resulting from schistosomiasis as it presents with non-specific manifestations and inconclusive laboratory and endoscopic findings.