Understanding The Causes Of Intestinal Obstruction
Intestinal obstruction involves a partial or complete blockage of the bowel that results in the failure of the intestinal contents to pass through. We do not realize the immense importance of the gut until it is obstructed.
Intestines have a vital function to perform, which is transport of food from oral to aboral end and absorption of it all along. The gastrointestinal secretions pour in response to food and it may work to six to eight litres. When the intestine gets obstructed the patient develops vomiting, colicky abdominal pain, distension of abdomen and absolute constipation. This is a surgical emergency and repetitive clinical examination is mandatory to decide on surgical intervention.
Obstruction of the bowel may be caused by Paralytic ileus in which the bowel doesn’t function correctly but there is no “mechanical” (anatomic) problem. It may be caused by a wide variety of mechanical causes. T
Causes of Paralytic Ileus:
- Medications, especially narcotics
- Intraperitoneal infection
- Mesenteric ischemia
- Injury to the abdominal blood supply
- Complications of intra-abdominal surgery
- Kidney or spinal disease
- Metabolic disturbances like decreased potassium levels
- Excess of fluid loss due to diarrhea can lead to potassium loss and this is one common cause of Paralytic Ileus. The bowel sounds are not heard.
Mechanical obstruction occurs when the movement of material through the intestines is physically blocked. When the block occurs in the large intestine the distension is huge and the spread of bacteria to the whole body occurs. The mechanical stretching leads to compromise of blood supply and hence gangrene of the bowel occurs.
The mechanical causes of obstruction are numerous and may include the following:
- Hernias
- Postoperative adhesions
- Twisting of gut called volvulus
- Tumors blocking the intestines
- Granulomatous processes (abnormal tissue growth)
- Foreign bodies ingested
- Round worms
It is a common abdominal emergency and in some communities the most common one. Some patients with simple obstruction resolve spontaneously. If the small gut is gangrenous, you will have to excise it and anastomose its ends. Unfortunately, patients with intestinal obstruction present late. He/she may be severely dehydrated, oliguric, and shocked. The biochemical milieu is altered and this leads to loss of Sodium and Potassium and the patient becomes seriously ill. In developing countries the intestinal obstruction is caused by hernias, in the developing countries adhesions and carcinoma of the colon are unusual. Their place is taken by ascariasis, volvulus of the sigmoid colon. In our country tuberculosis of the small intestines are very common.
When the obstruction is high, there is frequent vomiting, no distension, and intermittent pain. If the obstruction is in the middle of the small gut, there is moderate vomiting, moderate distension, and intermittent pain of the classical, colicky, crescendo type with free intervals.
When the obstruction is low in the small gut, vomiting is late and faeculent, and distension is marked. Pain may or may not be classical.
Treatment options:
Plain x-ray films of the abdomen help in deciding the site of intestinal obstruction, while in some you will need imaging studies like C T scan. The air-filled intestines can make interpretation by Ultrasound scans, difficult. The girth of the abdomen gives an idea of the obstruction and it is measured and recorded.
The patient with intestinal obstruction needs to be hospitalized for intensive surgical care. Intravenous fluids are administered and Ryle’s tube is inserted in to the stomach to decompress the distended gut. Antibiotics are given. Emergency intervention to relieve the obstruction may be necessary and the type of surgical procedure depends on the nature of obstruction. Some may require more than one surgery or intestinal diversion like colostomy.
When the bowel does not move and if the patient has colicky pain in the abdomen along with vomiting it could be intestinal obstruction. Do not take purgatives or painkillers. Majority have an uneventful post operative period while a small number may develop leak at the operative site in the intestines. When the obstruction is due to cancerous growth the patient requires further treatment.
