Intestinal histoplasmosis and coinfections mimicking inflammatory bowel disease and neoplasia

Objectives: to describe a case series of chronic diarrhea of infectious etiology previously identified as Inflammatory Bowel Diseases (IBD). Case reports: we present four cases from a Brazilian tertiary hospital in which patients with HIV were initially treated for IBD or suspected neoplasia based on clinical presentation and colonoscopy findings. Late-stage HIV/AIDS diagnosis subsequently revealed disseminated histoplasmosis with intestinal involvement and coinfections, including cytomegalovirus colitis (n = 3) and tuberculosis (n = 1). Conclusions: chronic diarrhea, particularly when accompanied by dysenteric symptoms, presents significant challenges in distinguishing between Inflammatory Bowel Disease (IBD), neoplasia, and infectious diseases. This case series highlights the importance of considering immunosuppression, especially HIV/AIDS and related opportunistic infections, in cases of chronic diarrhea. A comprehensive diagnostic approach incorporating microbiological, serological, molecular, and histopathological analyses is critical in identifying underlying etiologies, including coinfections. Early and accurate diagnosis facilitates appropriate treatment, reducing the morbidity and mortality associated with these conditions.