(A) H&E staining of the proximal resection margin, dilated segment, transition zone, and narrowed colon of HSCR and HAEC patients. Scale bars: 100 μm. (B) An enterocolitis grading system was used to evaluate inflammation. (C) CD68 and iNOS immunofluorescence double staining to identify M1 macrophages. Red, CD68; green, iNOS; blue, DAPI. Scale bars: 100 μm. Data shown are representative of n = 75 samples of HSCR patients and n = 21 samples of HAEC patients. One-way ANOVA: ***P < 0.001.