Intestinal Obstruction Syndrome

Intestinal obstruction syndrome is a condition in which the flow of air and contents in the intestines is obstructed, either due to blockage or paralysis of the intestines. It is a syndrome, not a disease.

Causes of Intestinal Obstruction:

• Functional Intestinal Obstruction: Loss of intestinal contractility due to neurological causes such as spinal cord injury causing paralysis, functional intestinal obstruction, peritonitis, electrolyte disturbances.

• Mechanical Intestinal Obstruction:

• Within the intestinal lumen: Food residue, worm balls, gallstones.

• From the intestinal wall: Congenital intestinal atresia, ileo-colonic UT, amoebic ulcer, tuberculosis ulcer, congenital or post-operative intestinal stenosis.

• From external compression: Abdominal tumor compression, ovarian cyst, intestinal torsion, congenital/post-operative ligaments, incarcerated inguinal hernia, internal hernia.

Nutritional status in mechanical intestinal obstruction:

• When the intestine is blocked: Blood supply is still good.

• When the intestine is constricted: Blood supply is disrupted, causing the intestinal segment to potentially become necrotic.

Causes of intestinal obstruction from the small intestine:

• Due to constriction: Intestinal torsion, incarcerated hernia, intussusception.

• Due to blockage: Gallstones, food residue, intestinal tumors.

• Other: Inflammation in tuberculosis.

Causes of intestinal obstruction from the colon:

• Due to constriction: Colonic torsion, incarcerated hernia.

• Due to blockage: Progressive cancer.

Intestinal torsion in the free loop: It should not be untwisted because of the risk of the patient going into shock due to toxins from inflammation and necrosis.

Pathophysiological disturbances in intestinal obstruction:

• Dehydration: Due to malabsorption and increased secretion in the intestinal loops above the obstruction, due to vomiting.

• Electrolyte disturbance: Primarily loss of Cl, Na, K.

• Nutritional disturbance: Accompanied by a decrease in blood protein due to reduced gastrointestinal absorption.

• Intestinal wall edema: Increases the obstruction and causes exudation into the peritoneal cavity, increasing blood volume.

High intestinal obstruction:

• Early vomiting – loss of acid – acid-base disturbance – metabolic alkalosis.

Low intestinal obstruction:

• Vomiting/no vomiting – acid-base disturbance – metabolic acidosis.

Local disturbances in intestinal obstruction:

• Intestinal dilatation: Causes:

• Intestinal wall circulatory disturbance, lack of intestinal oxygen leading to intestinal necrosis and perforation, increased permeability causing fluid leakage.

• Reduced intestinal wall muscle tone, decreased peristalsis, stagnation, bacterial growth, inflammation.

==> The two conditions above cause peritonitis.

Mechanism of peritonitis:

• Fluid and electrolyte retention:

• Reduced absorption and increased secretion.

• Intestinal wall edema.

• Increased permeability.

Systemic disturbances:

• Intestinal dilatation: Causes venous congestion leading to edema – increased permeability causing plasma loss + stagnation causing electrolyte loss.

• Vomiting.

• Stagnation, bacterial growth – intoxication.

==> Shock.

Systemic symptoms of intestinal obstruction:

• Usually present in patients who arrive late, including: Dehydration, infection, intoxication, shock (rapid pulse, low blood pressure).

Three cardinal symptoms of intestinal obstruction:

• Abdominal pain, vomiting, constipation.

Abdominal pain in intestinal obstruction:

• Mechanical obstruction: Intermittent pain, twisting pain, cutting pain, separated by periods of pain relief, pain starting suddenly and the intensity changing, the pain increases later, the duration of pain decreases, there is no posture to reduce pain.

Vomiting:

• After vomiting, the patient feels pain relief.

Constipation:

• The most important factor in diagnosis, if the obstruction is high, the patient may still be able to defecate.

Abdominal distention:

• Due to the accumulation of fluid and air in the intestinal loops above the obstruction.

• The higher the obstruction, the less distention.

• Distention is uniform or uneven (intestinal torsion).

Snake sign:

• An important symptom to differentiate between mechanical and functional intestinal obstruction.

Koenig’s syndrome:

• Abdominal pain, increased peristalsis, increased bowel sounds followed by defecation that relieves the pain, is a sign of partial small bowel obstruction.

Duval’s sign:

• Intermittent abdominal pain, sometimes lasting 2-3 days, pain resolves when defecation occurs, this sign is seen in partial colonic obstruction.

Percussion in intestinal obstruction:

• Tympany throughout the abdomen and dullness in the lower abdomen.

Auscultation in intestinal obstruction:

• Increased bowel sounds in early intestinal obstruction, decreased in late intestinal obstruction, absent in functional intestinal obstruction.

• It is a sign to differentiate between functional and mechanical intestinal obstruction.

Rectal examination in intestinal obstruction:

• Empty rectal pouch, mucus and blood in cases of intestinal torsion, rectal tumor, intussusception.

Examination of inguinal hernial orifices:

• Scrotum, thigh.

X-ray:

• High obstruction: Image of wide-based air-fluid level, low vault, arranged in a staircase pattern, from the splenic flexure to the right iliac fossa.

• Low obstruction: Image of narrow-based air-fluid level, high vault arranged along the colonic frame.

• May show fluid in the abdomen or only show dilated intestinal loops.

Ultrasound:

• Increased intestinal peristalsis, fluid in the peritoneal cavity, cause and location of the obstruction.

High intestinal obstruction:

• Obstruction in the small intestine.

Low intestinal obstruction:

• Obstruction in the large intestine.

Symptoms of high intestinal obstruction:

• Sudden abdominal pain, early and frequent vomiting.

• Early changes in systemic status: Dehydration, rapid pulse, low blood pressure, possible shock.

• Less abdominal distention, sometimes flat abdomen.

• Electrolyte disturbance.

• X-ray: Air-fluid level with wide base, low vault arranged in a staircase pattern from the splenic flexure to the right iliac fossa, sometimes with an accordion shape, no colonic dilatation.

• Small bowel obstruction is usually due to mechanical causes or due to ligaments, constricting the intestines, easily leading to early necrosis.

Symptoms of low intestinal obstruction:

• Gradual onset, vomiting/nausea/none.

• Few changes in systemic status for a long time.

• Abdominal pain is usually vague, less clear.

• Abdominal distention is significant, symmetrical or asymmetrical.

• Rectal or vaginal examination sometimes reveals a low-lying mass.

• X-ray: Dilated colonic frame filled with air. Air-fluid level image with narrow base, high vault located along the colonic frame.

Symptoms of intestinal obstruction starting suddenly and severely, early and frequent vomiting, repeated several times, continuous pain, no respite, rapid changes in the whole body:

• Suspect intestinal obstruction due to strangulation.

Vol Wahl ball sign in intestinal obstruction due to strangulation or twisting:

• Little or much abdominal distention, an intestinal loop stands out as a resilient ball, painful to touch, resonant to percussion, no intestinal peristalsis.

Pain in Douglas’ pouch in intestinal obstruction:

• Positive peritoneal response due to exudation of fluid into the peritoneal cavity.

X-ray in intestinal obstruction due to strangulation and twisting:

• Shows a single, dilated, bow-shaped intestinal loop with two air-fluid levels at the two ends of the loop.

Intestinal obstruction due to blockage:

• Pain starting gradually, less severe. Systemic status remains good for a long time. Significant abdominal distention, diffuse, with intestinal peristalsis (snake sign), little electrolyte disturbance in the early stage.

X-ray in intestinal obstruction due to blockage:

• Shows multiple diffuse air-fluid levels.

Note: This is a translation of the provided text. I have tried to remain as accurate and complete as possible, but there may be some nuances that are lost in translation. If you have any specific questions, please feel free to ask.