Defecation

Squatting stool

Seated bowel movement

Defecation ( lat.defecatio ; synonyms: emptying the rectum , stool , bowel movement ) - the process of excretion of feces from the digestive tract (in humans - from the rectum ) through the anus .

In humans, normal defecation occurs about once a day (from one to two times a day to once every two days). If bowel movements occur more often (frequent stools) or less frequently ( constipation ), this is usually accompanied by a change in the physical properties of the stool. Frequent stools usually have a more fluid consistency ( diarrhea ), even watery. When stool is delayed, feces become too coarse and hard and can injure the mucous membrane. Cases of rupture of the intestine with hard have been described, leading to peritonitis and fatal . As a rule, a violation of the frequency of bowel movements is a symptom of a disease and requires the advice of a doctor ( gastroenterologist , proctologist or surgeon ). Involuntary bowel movements sometimes occur during childbirth .

Content

Physiological parameters

Defecation in a healthy adult is characterized by the following physiological parameters:

The threshold of rectal sensitivity (the minimum amount of feces necessary for the appearance of a feeling of intestinal fullness) is less than or equal to 25 ml;
The minimum volume for relaxing the internal anal sphincter (the volume at which the first urge to defecate occurs) is 10-20 ml;
The threshold for a constant urge to defecate (the volume required for the appearance of a constant urge) is less than or equal to 220 ml;
The maximum tolerated volume is 110-280 ml.

The listed parameters are measured by the method of anorectal manometry and their deviations from the norm are diagnostic signs. ^[one]

With bowel movements and outside it in an adult, 0.1-0.5 liters of gas is normally excreted from the intestines per day. With flatulence, the volume of gas released can reach three or more liters. The composition of the gas mixture in healthy people is as follows: nitrogen N ₂ - 24–90%, carbon dioxide CO ₂ - 4.3–29%, oxygen O ₂ - 0.1–23%, hydrogen H ₂ - 0.6–47% , methane CH ₄ - 0–26%, as well as a small amount of hydrogen sulfide H ₂ S, ammonia NH ₃ , mercaptan ^[2] , and scatol .

Defecation in children

The call to the act of defecation occurs when the feces are moved from the sigmoid colon to the ampoule of the rectum , but the act of defecation in humans is controlled by the central nervous system . A healthy child is able to suppress the urge to defecate, starting from the age of one and a half to two years. In a child, the normal stools are the third and fourth types, determined by the Bristol scale of the stool , namely, in the form of sausages with a ribbed surface or in the form of a smooth and soft sausage. ^[3]

Healthy children have the following age-dependent number of bowel movements per week:

up to three months, breastfed - from 5 to 40;
up to three months, who are on artificial feeding - from 5 to 20;
from 6 to 12 months - from 5 to 28;
from a year to three years - from 4 to 21;
over four years old - from 3 to 14. ^[3]

Notes

↑ Stendal Ch. Practical Guide to Gastrointestinal Function Testing. Blackwell Science Ltd., 1997, 280 p. ISBN 0-632-04918-9 . (eng.)
↑ Human physiology . Under. ed. V. M. Pokrovsky, G. F. Korotko. M.: Medicine, 2007, - 656 p. ISBN 5-225-04729-7 .
↑ ¹ ² Privorotsky V.F., Luppova N.E. Modern approaches to the treatment of functional constipation in children . RZHGGK. - 2009. - T. 19. - No. 1. - P.59-65.

Links

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[StC-1] Stendal Ch. Practical Guide to Gastrointestinal Function Testing. Blackwell Science Ltd., 1997, 280 p. ISBN 0-632-04918-9 . (eng.)

[PoK-2] Human physiology . Under. ed. V. M. Pokrovsky, G. F. Korotko. M.: Medicine, 2007, - 656 p. ISBN 5-225-04729-7 .

[PrLu-3] ¹ ² Privorotsky V.F., Luppova N.E. Modern approaches to the treatment of functional constipation in children . RZHGGK. - 2009. - T. 19. - No. 1. - P.59-65.