[Validity of ano-rectal manometry in the diagnosis of cathartic colon as a cause of chronic pseudo-obstruction of the colon. Considerations on a case].

Cathartic colon is a rare pathology which hits old people and is radiologically characterized by dolichocolon and megarectum. It is nearly sure that the unusual length of the whole colon might be the first source of the cathartic disease. Rectal ampulla dilatation (megarectum) is due to the extended use of laxatives which induce changes in smooth muscle and in the myenteric nervous plexus. The anatomo-pathological changes of the rectum have been proved so far by histological examination of local and deep biopsy; now, in our opinion, they can be shown by manometry. The authors emphasize the possibility that cathartic colon might give episodes of diarrhoea and also recurrent bowel obstructions limited to the colon and so-called "chronic pseudo-obstruction" of the colon. They describe a case of this rare pathology admitted and treated in their ward. Gastric and esophageal motility in the patient was normal as was the motility of the upper rectum. Therefore they think that changes resulted from extended use of cathartics. In both cases patients show low manometric pressure, disordered peristalsis and in particular lack of internal anal sphincter relaxation in response to high balloon distension. As the occlusive status developed in an old patient (the patient was 81 years old), the authors think that the functional disorders were absent at birth. Cathartic colon is, in the authors experience, a cause of chronic pseudo-obstruction of the colon. Rectal manometry makes it possible to avoid surgical treatment. The therapy of pseudo-occlusion, if correctly diagnosed, consists in endoscopic intubation and decompression of the colon.(ABSTRACT TRUNCATED AT 250 WORDS)