Hi, this is Dr. Buck Parker, MD, General Surgeon. In this post I want to talk about bowel obstructions. Often I see patients who come into the emergency department with a bowel obstruction and don’t quite understand what this is or how it happens. These are a couple of things I want to clear up in this post.
First, what do I mean by a “Small Bowel Obstruction”. Well, lets first start with a little anatomy. The “Gastro-intestinal tract” or “GI tract”, is basically a long muscular tube that goes from your mouth to the anus. It’s the tract the food follows all the way through your body. There are a few main parts. The mouth, esophagus, stomach, small bowel, large bowel (or colon) and anus. So the small bowel is in between the stomach and the colon, and basically lives in the abdominal cavity with the stomach and colon. The small bowels are pretty incredible when you think about them, because they essentially absorb all the nutrients you put in your mouth. The stomach functions to grind the food up, the colon solidifies the waste, but the small bowels do the real work, by taking that ground up food and placing it in your bloodstream…..pretty amazing.
Anyway, the small bowels are fairly “loose”….by this I mean they are not really attached to much. They are allowed to toss and turn so they can keep the food moving downstream all the while absorbing all the nutrients. In a rudimentary way, they are kind of like a “can of worms” moving all around themselves.
Since they are basically a muscular tube, if that tube becomes blocked somehow, then this is what we term a “Small Bowel Obstruction”. I know you’re probably asking yourself right now, “how the heck do they get blocked up….by food?”. Well, that’s sort of true. What actually happens is somehow, something on the outside of that tube is narrowing the tube, or kinking the tube for various reasons. The two most common reasons are hernias and adhesions (otherwise known as internal scar tissue). If you are unfamiliar with hernias, see my posts and videos on hernias.
Let’s talk about adhesions. Adhesions are basically “scar tissue” on the inside. Anytime someone has an operation on the belly (like a gallbladder removal, or appendix removal for example), we develop scar tissue on the inside of the belly. This scar tissue is a little strange…..probably due to the amazing small bowels. This scar tissue tends to change over time. It mostly changes shape, and not really location so much….but together with the constantly moving small bowels, this can put the contents of the abdomen in a very precarious position. What I mean by that is that the scar tissue can wrap around the outside of the small bowels, or attach a portion of the small bowels to inside wall of the belly. Then, as the small bowels move around, this can compress the small bowel tube, or kink it off. So when the food tries to sneak by this spot, it can’t….it’s blocked. Now have a small bowel obstruction.
So what ends up happening is that the food or liquid you put into the stomach, which goes onto the small bowel, gets backed up at the spot of obstruction. Not only does it get backed up, but the small bowel tube gets bigger and bigger to try to accommodate all this new food and liquid. And even if you stop eating and drinking, the stomach, liver, pancreas and small bowels can produce up to 4-5 liters of fluid per day. So you can see how this can rapidly become a problem.
As the small bowels become distended, they contract as they try to push through the food and liquid. But if there is a COMPLETE obstruction, the contractions will be useless and only cause crampy waves of pain when the bowels are contracting. If there is a PARTIAL obstruction, the contractions may cause crampy waves of pain, followed by relief for a little while as some of the food and liquid go through, then pain again as the bowels distend and contract against the partial blockage.
Well, I guess I’m going a bit backwards on this post, but lets talk a little about the symptoms of a small bowel obstruction. Although there are a few symptoms that are seen in bowel obstructions, unfortunately they are seen an many other illnesses as well. Nausea, vomiting, abdominal pain and distention are among the most common symptoms. You can have all or some of these, but the REALLY telling symptom is obstipation. Obstipation is when you stop passing flatus or “gas from below”, as I like to delicately put it. If you develop obstipation, then we can be more confident in diagnosing a bowel obstruction.
I hope you gained a little insight to the diagnosis of small bowel obstruction, and be on the lookout for my other posts describing diagnostic studies generally used and the usual treatment course. Talk to you later,
P.S. Please leave any questions or comments for me below! Thanks!