This type of clinical presentation is more similar to a colonic infection than to inflammatory bowel disease (IBD), so the first step is to carry out laboratory blood tests (complete blood count, metabolic panel, erythrocyte sedimentation rate, C-reactive protein, viral DNA-PCR, tissue transglutaminase IgA, and total IgA) and stool tests (Clostridioides difficile, stool cultures, ova and parasites, fecal elastase, and lactoferrin or calprotectin). The gene discussed is LTF; the disease is inflammatory bowel disease.