Rectal histopathology was evaluated in 34 cases (2 months-12 yrs old) of endemic “invasive diarrhea” [>20 WBCs per high-power field on stool microscopy with (RBC positive) or without (RBC negative) associated RBCs] whereS. dysenteriae(n= 9),S. flexneri(n= 11), and nontyphoidalSalmonellawere isolated as the sole identifiable enteropathogens. Persistent diarrhea (>14 days duration) was more common withSalmonellainfection whereas RBC-positive “invasive diarrhea” was more frequent withShigella,particularlyS. dysenteriae(all cases) infection. The histopathological profile was comparable to the earlier descriptions of infective colitis to a large extent and the nature of the infecting organism could not be determined on the basis of rectal histology alone. The other noteworthy features were as follows: (i) mild crypt distortion (26%) and branching (21%) in bothShigellaandSalmonellainfection; inSalmonellainfection, dilation of the glands was significantly greater with persistent diarrhea; (ii) presence of chronic inflammatory cells either alone or in combination with neutrophils in 62%; a predominant neutrophilic response was significantly higher withS. dysenteriaeinfection and an acute presentation; (iii) pseudomembrane formation (six subjects; 18%) especially inS. dysenteriae(four cases); and (iv) a significant association of neutrophilic response, edema, and neutrophils within the vessels in the lamina propria and mucin depletion in the glands with RBC-positive “invasive diarrhea.