1446 THE MISUNDERSTOOD BOWEL

THE MISUNDERSTOOD BOWELRADIOGRAPHY has changed our conception of

the movements of the large intestine. It is now

recognised that the fluid contents of the ileum

pass fairly continuously into the caecum and

ascending colon, which are filled by pressure from- above. At intervals a mass movement takes

place which propels the faeces rapidly along thetransverse colon and into the sigmoid. Thismovement may produce a call to defaecation or

may merely fill the distensible sigmoid. Thecolon thus normally contains a considerable

quantity of food residue, fluid in the proximalsection and more solid in the distal, the greateramount being in the caecum and sigmoid. Thisfact has been confirmed at autopsy on soldiersand others who have died violently, as well ason the X-ray screen by FIESSINGER and HUTET.1The normal colon is largely filled with a mixedresidue of the meals taken in the previoustwo to five days, and this fullness causes the hostno discomfort. The call to defaecation is producedby distension of the rectum, due either to faecesbeing pushed in by the mass movement from above,or to an enema from below. Defaecation emptiesthe whole of the left colon and sigmoid, leavingmainly liquid faeces in the caecum and ascendingcolon.So much for the healthy gut. Fiessinger and

Hutet 2 have lately given patients on a normal dieta small amount of barium emulsion before their

evening meal for several days, and have followedits progress radiologically. They find that thereis actually little difference between the colons ofnormal and constipated people: both contain themixed residues of several days. In the constipatedperson, however, the mass movement that carriesthe faecal column onwards from the hepatic flexureis ineffective, so that there tends to be an accumula-tion of faeces in the proximal half of the colon.In slightly costive people-those whose bowels

open sometimes without help and sometimes needthe aid of mild laxatives-the large intestine is

nearly full. Paradoxically it is only the severelyconstipated who have an empty colon-thosewho take regular purgatives or a greatly restricteddiet. In such cases the patient may develop anabnormal sensibility to the fullness of his colon,and the desire to keep it empty may become anobsession. Even when it is empty, spasm asso-ciated with irritation of the mucous membrane

may still give a sensation of fullness. This formof constipation, which is common enough, Fiessingerand Hutet call " constipation by deficit."

Defaecation is a conditioned reflex shared byman with other house-trained animals, and allcases of functional, as distinct from organic,constipation are due to interference with thisreflex. To the layman constipation is difficultywith defaecation, whatever the cause, and he baseshis diagnosis on the absence of the regular dailysensation of distension in the rectum which is

1. Fiessinger, N., and Hutet, G., Arch. Mal. Appar. dig. 1933,23, 689.

2. Fiessinger and Hutet, Pr. méd. April 22, 1939, p. 611.

the detonator of the reflex. In some cases

persistent inhibition of the reflex may have reducedthe sensibility of the rectum so that its owner nolonger knows when it is full, and here cure mustdepend on training and encouragement. But

usually any but the smallest quantity of faeces inthe rectum produces discomfort, and defeecationwill be normally carried out if the rectum is

regularly filled. To attain this goal the constipatedperson must aim at keeping his colon full, notempty, so that he can take advantage of the massmovement in the colon when it comes. This callsfor a high-residue diet rich in fruit and vegetablesand the substitution of purgatives by mucilagessuch as psyllium seeds which add bulk to thefaeces. Such measures can be seen radiologicallyto restore the normal filling of the colon, and withit a daily action of the bowels. These facts cannotbe too widely advertised among our purgative-ridden generation seeking for a sign.

ASSAY OF SEX HORMONES

BESIDES being an indispensable means ofstandardising important therapeutic materials, thebiological assay of sex-hormone activity is a

potentially valuable means of estimating endocrinefunction in individual patients. The soundness ofthe methods employed is accordingly a matter ofconcern not only to the laboratory endocrinologistbut also to the clinician. If the latter is to prescribehormone preparations which are not chemically puresubstances, and which therefore have to be assayedon laboratory animals, he must have confidence inthe system of biological assay. Again, if he seekshelp from the. laboratory in making a diagnosis,and is told that the urinary excretion of a hormonedeviates from the normal, he must be sure thatthe methods used are quantitatively accurate. Forthese reasons the publication of two critical studies 1 2on these subjects will be welcomed, though theirconclusions are in some respects disturbing.The Medical Research Council has for many years

promoted research into biological standardisation,and the report by Mr. EMMENS on the variablesaffecting the estimation of androgenic and oestro-genic activity illustrates the traditional combinationof painstaking laboratory work with statisticalappraisement of the results. Though the mathe-matical treatment appears formidable, this verytechnicality will be a virtue if it convinces the lessspecialised reader that proper " hormone assay " ismore easily said than done. The first section dealswith the technique of assaying crystalline cestrogens(oestrone, cestradiol, and oestriol) on ovariectomisedmice, the effect of changes in sensitivity of thecolony of mice, and the factors-such as subdivisionof the dose injected, and presence of augmentorsubstances-which may influence the response and

entirely alter the apparent relative activity of

1. Reports on Biological Standards: V. Variables Affecting theEstimation of Androgenic and Œstrogenic Activity. ByC. W. Emmens, M.Sc. Spec. Rep. Ser. Med. res. Coun.,Lond. No. 234. London: H.M. Stationery Office. 1939.Pp. 71. 1s. 3d.

2. Comparative Studies Concerning the Strengths of ŒstrogenicSubstances. By K. Pedersen-Bjergaard. London :Humphrey Milford, Oxford University Press. 1939.Pp. 198. 15s.