Constipation or Constipation

Edited by Dr. Massimo Massari

Definition

The term constipation is defined as the slowing of the progression of the contents of the colon, up to its expulsion through the emptying of the rectal ampulla by means of evacuation. There are actually two forms of constipation: propulsion constipation, commonly defined "constipation", actually linked to slowed transit, and expulsion constipation, technically defined as "out-flow". In this second case the difficulty of the patient consists in the partial or total inability to evacuate. To better understand this complex physiological activity, it is good to know in a little more depth the dynamics underlying the function of the colon. The intestinal contents arrive in the colon in liquid form; the primary function of this organ is represented by the reabsorption of the liquid part and from the final expulsion of digestion products. The colon is equipped with its own Semi-Autonomous Nervous System, called Enteric Nervous System (ENS); the main functions of the ENS concern:

the production of Serotonin, a substance responsible for the functioning of the colon muscles.
This action, in particular, is sensitive to the interrelation between the ENS and the Brain (Central Nervous System - CNS); so-called "brain-gut axis" (theory of two brains) literally "brain-gut axis".
Basically, external stimuli received by the CNS can cause an "action of excessive stimulation to the production of serotonin or block its" action; this will result in an accelerated transit in the colon (diarrhea) or slowed down (constipation).
the regulation of the permeability of blood and lymphatic vessels, typical of the colon and located immediately below the mucosa (the internal surface of the colon lining) responsible for the reabsorption of the liquid part of the contents of the colon;
immune regulation, through the ability to recognize the harmful substances that we introduce with food (eg traces of pesticides, viruses, parasites, etc.), thus activating all the organic functions of protection and rapid expulsion of these substances from our body.

Symptomatology

The symptomatology essentially consists in the inability to daily expel the residues of food digestion by emptying the rectal ampoule.
When this physiological function is performed less frequently (once a week or even every 10-12 days) we speak of stubborn constipation.
In addition to the inability to evacuate, the symptomatological kit is characterized by: slow digestion, feeling of abdominal bulk, abdominal swelling, easy fatigue up to general malaise and irritability of the mood.
Furthermore, in cases of obstinate constipation, evacuation is often, necessarily, induced by the use of cholagogues (laxatives), taken orally (syrups, herbal remedies, etc.), emollients taken trans-rectally (glycerin in suppositories , mini evacuation clips, etc.), or the need to use manual emptying of the rectal ampulla.

How the diagnosis is made

A correct diagnosis of constipation must necessarily allow the distinction between propulsion constipation and out-flow constipation.
Diagnostic investigations must also exclude the presence of colon diseases that obstruct the lumen of the bowel and prevent the transit of digestive residues.
Basically, the following must be performed:

the endoscopic study of the colon, to exclude, as mentioned, obstructive pathologies (bulky polyps or colon tumors, presence of anal fissures);
the radiographic study of "transit times", it is an X-ray examination performed in two successive sessions, after the "ingestion of radiopaque" markers "(small rubber dots) which, mixed with digestion residues, run through the entire colon up to expulsion (photos 1 and 2)

Photo 1

X-ray of the abdomen 24 hours after taking the radiopaque markers (white dots) most of which are present in the right colon

Photo 2

X-ray of the abdomen 8 days after taking the radiopaque markers (white dots), most of which have not yet been eliminated and are visible in the left colon

Physiologically, the markers must have been completely expelled within 48 hours of their ingestion. A deficit of propulsion of the colon will result in the non-expulsion of the markers and their distribution in the various segments of the bowel.

Anorectal manometry

To understand the importance of this absolutely painless examination, it is necessary to know the dynamics of the expulsion of digestion residues.
This physiological act involves: the "rectal ampulla, which contracts when a certain amount of digestion residues has accumulated inside it (usually 150 cc); the anal sphincter, normally tonic and responsible for continence, is released to promote" expulsion of rectal contents; the muscles of the pelvic floor, which contract to favor the expelling action of the contents of the rectal ampulla.
The synergy of these three acts allows a physiological emptying of the rectal ampulla; when this synergy is lacking we speak of "out-flow" constipation, in other words an "inability to empty."
The study of the reaction of the muscles of the rectal ampulla to distension, the tone of the sphincter, anal and its ability to relax; the study of the ability to contract the muscles of the pelvic floor are indicated with the term "anorectal manometry'.

Cinedefecografia

The dynamics of the synergy of the three described actions is also evaluated through cinedefecografia.
This radiological examination consists in the radiographic visualization of the rectal ampulla through the use of a small amount of contrast medium (barium).
The simulation of an evacuation, during the execution of the radiographs, allows to quantify the effectiveness of the contraction of the pelvic floor muscles, and their relationship with the rectal ampulla.

Photo 1

barium cylinder in the rectum in the resting position

Photo 2

modification of the axis of the barium cylinder,
relative to the plane of the pelvic floor,
during contraction of the muscles of the
pelvic floor, in evacuation