Laboratory results revealed: severe anemia (Hb 6.7 g/dL, MCV 68 fL), leukocytosis (14.37 × 103/μL), elevated CRP (99.4 mg/L), acute kidney injury (creatinine 3.38 mg/dL, ref. 0.57–1.11 mg/dL; urea 104 mg/dL, ref. 17.00–50.00 mg/dL), and fecal calprotectin was elevated of 190 μg/g. This evidence concerns the gene GSTM1 and anemia (phenotype).