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This is Pediatrics case number four and the

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diagnosis were considering is hirschsprung disease.

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This patient is within the

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first few days of life.

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And we know that the main indication or

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concern that leads us to

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do a test to evaluate for hirschsprung disease is failure to

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pass meconium. Most pediatric experts will

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say that the newborn should

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pass meconium in the first day of life and certainly by

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the first 72 hours of life. So if we get to four days

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with failure to pass meconium, we

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know that there's something not quite right and this

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is a frontal radiographic image

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of the abdomen and what I want to draw your attention to is what

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you don't see so what you don't see is bowel

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gas all the way throughout the

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abdomen.

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and

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there's various Loops of gas

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filled bowel up here. No problem

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these look normal, but down here in the pelvis at

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the area of the rectum. There's nothing

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and so that's by itself not evidence

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of hirschsprung disease, but it is concerning when combined with

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the history of failure to pass meconium. So

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I'm going to step us through what this exam actually

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is not a radiograph alone, but a fluoroscopic

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enema again as with our prior

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case of meconia Milius we use water soluble contrast in

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children, and as we mentioned previously

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we don't use a balloon and that's especially important

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when we're considering the caliber of the

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rectum. So even if it's not a premature baby, even if

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it's not a newborn sometimes hirschsprung is diagnosed late

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if it's partial or you know in completely

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You symptomatic hersprung disease. We still don't want to use that

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balloon because it can distend the rectum and some sources.

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This is controversial but some sources say

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it can completely obscure the diagnosis

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you can decide for yourself. The literature is

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a little unclear on this point, but

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I think as a good rule of thumb you can't run into

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problems by not using a balloon.

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So you tape in your catheter you begin to infuse contrast the

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first images of this exam are very critical. So

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you can see here's our catheter and just a tiny

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bit of contrast has been infused into a largely collapse direct

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and we're gonna distend that with contrast and move that

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contrast retrograde. So I'm just going to step us through the images of

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this enema here. We've begun to fill

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We're into the sigmoid colon.

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And then we're stepping over.

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into the descending colon

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looping around there it is and moving up.

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To the transverse colon coming across the top of

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this image.

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Back down to the ace ending colon.

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And here's the cecum and you can see we've even opacified

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Some Loops of small bowel. Maybe even the

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appendix is in there.

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This is all contrast that his spilled outside

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of the patient. We can ignore that. So what

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are we most interested in discovering on this

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exam? Well, the caliber of the Colon's normal. We're not

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worried about that. There's no sign of obstruction. What do we

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actually want to look at is we want to go back and evaluate

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the rectum at the very earliest images

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of the study. So this is the end of the study you can see there's

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been a lot of spilling going on that'll often happen because the

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pressure inside the bowel can sometimes push

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back against the passive infusion of contrast. We're

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not injecting this contrast. We're just letting gravity draw

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it down out of the bottle through the tubing into the

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colon of the patient.

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If those pressures become equalized or the intra-abdominal pressure

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is higher than the contrast starts leaking out. So we've

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made a bit of a mess here on our exam. I'm going to take us all the way

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back to the initial images of the rectum.

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And what you can see is there's a

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very tight narrowing at the distal rectum. And

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then it abruptly becomes quite large in

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caliber that is not a normal transition. And

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sometimes you'll hear sources talk about the recto sigmoid ratio

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should always be greater than

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one. You don't want your rectum to be

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smaller. You want the rectum to be bigger than the sigmoid colon?

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And as we look at some of these images we can see the

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distal rectum is tight it

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never fully opens up and that's because it's a

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ganglionic. It doesn't have the neural plexus that

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allows it to stand and that's causing obstruction. In

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fact in this case. It's causing a failure.

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to pass meconium

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the surgeons have different procedures where they can

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go in and remove Those egg-ganglionic portions of

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the colon.

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Now sometimes the Imaging is difficult. Sometimes it's

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equivocal and you might have a very small segment

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of the rectum and you're kind of on the fence is this disease

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or is it too small to

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really count?

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Give yourself some time to make the diagnosis obtain an

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x-ray of the abdomen the next

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morning because even if your catheter is

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obscuring the visualization, you didn't catch the image right

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at the beginning of the exam you're frustrated because you're on the

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fence if by next morning, they're still contrast

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sitting in the rectum 24 hours later. That's very

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concerning that the colon is not able to empty

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because of that a ganglionic portion. So give yourself

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some time watch how the body responds that can

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be an important clue. That's the end of our case.