Colonic Obstruction Due to Blastocystis hominis Infestation: A Rare Case Report

Case ReportA 47-year-old male patient was referred to the general surgery clinic with complaints of abdominal pain, recent constipation, intermittent fever, and weight loss.He had no known ABSTRACTBlastocystis hominis (B.hominis) is an intestinal parasite that is usually asymptomatic and transmitted by the feco-oral route.It is commonly found in human and animal fecal samples.The role of Blastocystis in human health and disease is controversial.Studies have shown a relationship between subtypes and symptom presentation.Patients frequently present with abdominal pain, nausea, bloating, and diarrhea.In our case, intestinal obstruction was observed, which is the exact opposite of the usual B. hominis symptoms.The patient was evaluated for malignancy.On radiologic examination, the appearance of an almost complete obstruction of the distal sigmoid colon passage was highly suspicious of malignancy.An endoscopic evaluation revealed a mass almost completely obstructing the lumen.Malignancy was not pathologically confirmed.We performed surgical treatment in accordance with oncologic principles.This study aimed to share our experience in the diagnosis and treatment of an obstructive mass caused by a single-celled organism.