Diarrhea and Constipation

Basic Principles

Classification: acute or chronic; infectious; secondary to organic disease

Principal signs and symptoms:

Diarrhea

- more than four bowel movements per day

- stool weight i 250g/day

- soft or liquid consistency

Constipation

two or fewer bowel movements per week

stool volume significantly below the normal range of approximately
80–150 g/day

hard consistency

The passage of stool may or may not cause discomfort. Stool may be mucuscovered, bloody, watery, or granular and may contain grossly visible food
residues.

Diagnosis

The history is of key importance, as bowel habits are interpreted differently by
different examiners. A stool examination may be helpful.

All patients with diarrhea should be evaluated for the presence of an infection
and for organic disease. Blood work should be done and may include tests for
infectious organisms (blood culture, complement binding reaction). The stool
may also be examined for bacteriologic testing and antibody detection (e.g.,
clostridium antibody).

All true cases of chronic constipation are presumed to be caused by a stenosing
lesion.

Only a few causes of diarrhea and constipation can be diagnosed with ultrasound. Most cases should be investigated by endoscopy with tissue sampling
and histologic evaluation.

The differential diagnosis is reviewed, where the possible diagnoses
are listed in order of their frequency in the general hospital setting.