The Normal Colonic Flora
The normal colonic flora is usually inferred from the
composition of the normal faecal flora, since
suitable techniques for sampling various levels of
the colon have yet to be developed. Data from animal
studies would support the assumption that the flora
does not alter during defaecation, indicating that the
faecal flora adequately represent that of the rectosigmoid.
We know that the flora of the recto-sigmoid
differs from that at the ileocaecal junction (table I)
and can infer, but no more, that the change takes