The term “bowel obstruction” simply describes that the passage of food is somewhere obstructed in the bowel. This can occur in the small bowel (most often), called small bowel obstruction, or in the large bowel (not as common), called large bowel obstruction. It also can be congenital in a newborn or acquired in an adult. There are a number of different mechanisms that can cause bowel obstruction and I will describe these below.
Bowel obstruction is always a n emergency as the bowel can only survive without blood supply for a few hours, Then it ruptures and the content of the bowel would cause acute peritonitis.
The child or the adult who is affected by this condition is in excruciating abdominal pain and needs to be brought to the nearby hospital by ambulance where investigations can start right away and the surgeon on call is called in.
Symptoms and treatment protocols are different for children and adults, so there is usually a distinction made between them.
See this link for Small And Large Bowel Obstruction In Children.
Bowel Obstruction In The Adult
In the adult the causes of bowel obstruction are not usually congenital in nature, but are acquired. A common classification is to distinguish between small and large bowel obstruction.
See this link for Large Bowel Obstruction In Adults.
Small Bowel Obstruction In The Adult
As indicated earlier, with small bowel obstruction is more acute in its presentation as a lot of fluid can be lost into dilated small bowel loops. There might have been a history of prior surgery and bands of scar formation(= adhesions) have developed. These bands of scarring are made up of tough connective tissue and attach to bowel loops from outside like suction devices that won’t let go. As the years go by the adhesion tissue loses water and retracts thus leading to kinking of the attached bowel loops. This is when small bowel obstruction suddenly develops.
There might have been a few months or even years where the patient felt discomfort after meals. But then it settled again until that one day when it takes off. At that point there is acute abdominal pain in the right and central abdomen, somewhat dictated where the obstruction is. Also, if there is a volvulus present, where a bowel loop has turned around itself and the circulation is cut off, the symptoms are more pronounced and there is a higher priority for the physician to get in and rescue the bowel. There are only up to 6 hours before the bowel becomes gangrenous and there is a danger of perforation and peritonitis! Abdominal x-rays are quickly done, which often show a ladder like formation of bowel loops with fluid levels in the standing views. There is usually no cancer found in small bowel.
It is important to get an assessment by a surgeon early on in these cases. A laparotomy is arranged (=surgical opening of the abdominal cavity), which usually shows the cause of the obstruction right away. About 25% to 30% of the small bowel obstructions are strangulating (volvulus like). The surgical procedure depends on the findings during the laparotomy and on the status of the patient at the time of surgery. Often there might have to be a period of 2 to 3 hours prior to surgery where the bowel is decompressed by placing a naso-intestinal drainage tube first , replacing the fluid loss and balancing the electrolytes based on blood tests. When the patient is stabilized in this manner, the surgical procedure is safer and the complication rate is lower.
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