Welcome back to the channel where medical topics are made easy.
This video is about to save you a lot of time studying and will tell you exactly what you
need to know about diverticular disease.
So make sure to watch until the end.
We’re going to walk through and explain diverticulitis vs diverticulosis, along with
the symptoms, signs, diet, pathophysiology, diagnosis, treatment, and much more.
This video is great for nursing, students, and anyone who wants to learn more about diverticular
disease.
So let’s get right into it.
You can find the PDF notes and study guides for the video linked down below.
The terms diverticulum, diverticula, diverticular disease, diverticulosis, and diverticulitis
can cause confusion due to their similarities.
So let’s start off by defining them!
Let’s start with diverticular disease. Diverticular disease is the umbrella term
for the conditions involving the presence or formation of diverticula.
So what is a diverticulum or diverticula?
A diverticulum is a small, sac-like outpouching along the wall of a hollow structure.
The term diverticulum typically refers to an outpouching along the wall of the GI tract,
most commonly the colon or large intestine.
The term diverticula is the plural of diverticulum, and is used to describe more than one outpouching
or multiple outpouchings.
So as we said before, diverticular disease is the umbrella term for conditions involving
the presence or formation of diverticula which are these outpouchings in the colon.
Examples of diverticular disease include diverticulosis, diverticulitis, and diverticular hemorrhage.
You may see some textbooks use the term diverticular disease to describe symptomatic diverticula
only.
In other words, when someone has a diverticulum it’s not considered diverticular disease
until it becomes symptomatic.
However the umbrella definition used in this video is more widely accepted.
Let’s start with diverticulosis.
Diverticulosis is simply the presence of diverticula in the colon, usually without any related
complications or symptoms.
Diverticulosis carries a risk of progressing to other forms of diverticular disease, such
as diverticulitis and diverticular hemorrhage.
Moving on to diverticulitis, this is inflammation of a diverticulum.
Remember from our medical terminology video that “-itis” means inflammation.
Diverticulitis can be categorized into uncomplicated or simple vs complicated based on the presence
or absence of complications.
Finally we have diverticular bleeding or hemorrhage which is when a diverticulum bleeds.
We’re going to walk through each of these conditions in this video.
But first here is a quick summary of the definitions we just went over.
Make sure you save this for later and hit pause to review them.
In order to better understand diverticular disease, let’s quickly review the anatomy
of the colon, along with the blood supply and function of the colon.
The terms colon, large bowel, and large intestine all mean the same and can be used to describe
the colon.
The cecum is the pouch that forms the first part of the colon and connects the small intestine
and large intestine.
The rectum forms the last part of the colon.
The colon stretches from the cecum to the rectum in 4 parts.
Going in order, first we have the ascending colon,
then we have the transverse colon, followed by the descending colon,
and then we have the sigmoid colon which connects to the rectum.
On average the colon is approximately 5 feet or 1.5 meters long.
We’re just going to touch very quickly on the embryology of the colon.
The colon embryologically is both a midgut and hindgut structure.
The cecum, ascending colon, and proximal 2/3rd of the transverse colon develop from the midgut.
The distal 1/3rd of the transverse colon, the descending colon, the sigmoid colon, and
the rectum are all derived from the hindgut.
So you can see how the first part of the colon up to the black line develops from the midgut
and the rest of the colon is from the hindgut.
The ascending and descending colon are retroperitoneal, meaning they are found in a space between
the peritoneum of the abdomen and the posterior abdominal wall.
The rectum is also retroperitoneal.
The transverse and sigmoid colon, along with the cecum, are intraperitoneal structures.
You can see how the retroperitoneal and intraperitoneal structures form an alternating pattern.
You can learn more about the peritoneum in the body cavities and membranes lecture linked
in the description.
Let’s quickly review the walls of the colon as this will be important when we talk about
diverticula.
The walls of the bowel consist of 4 layers.
The inner lining of the colon is the mucosa.
Then outside of that is the submucosa.
Then we have the muscular layers which consist of an inner circular and outer longitudinal
layer.
The outermost layer is the serosa.
The outer layer of longitudinal muscle forms 3 long strips along the colon, called taeniae coli
which contract to form “pouches” along the colon, called haustra.
It’s important to remember that haustra are not the same as diverticula.
The colon is also decorated by small fat sacs of serosa called epiploic appendages.
These structures are hallmarks of the large bowel.
Let’s quickly review the blood supply of the colon as well.
The blood supply to the colon is split.
First we have the aorta.
The superior mesenteric artery branches off of the aorta.
Branches of the superior mesenteric artery supply the ascending colon and most of the
transverse colon.
These branches include the middle colic, right colic and ileocolic arteries.
The inferior mesenteric artery also branches off of the aorta.
Branches of the inferior mesenteric artery supply the descending and sigmoid colon.
These branches include the left colic and sigmoid arteries.
The rectum is supplied by 3 main arteries.
The superior rectal artery arises from the inferior mesenteric artery.
The middle rectal artery arises from the internal iliac artery.
And the inferior rectal artery arises from the internal iliac branches of the internal pudendal
arteries.
Finally, let’s review the function of the colon and we’ll get into diverticular disease.
The function of the colon is to absorb water and electrolytes from the small intestine
output, and convert it into solid feces.
The majority of the large intestine water and electrolyte absorption occurs at the ascending
and transverse colon.
However, it’s important to remember that the majority of water has already been absorbed
by the small intestine.
Now that we have a good understanding of the colon, let’s talk about diverticular disease
starting with the location.
Diverticula predominantly occur in the left side of the colon, particularly the sigmoid
and descending colon.
Other areas may be affected as well, although this is less common.
So how do diverticula form?
A diverticulum occurs when the mucosa and submucosa layers of the bowel herniate through
points of weakness in the colon.
These areas of weakness are located at points where small branches of blood vessels, called
the vasa recta, penetrate through the colon muscle wall to supply the bowel with blood.
The pathophysiology as to why diverticula form is not fully understood.
However, it’s believed that increased colon pressure, such as from constipation or straining,
causes weak spots in the colon to bulge out.
The risk factors of diverticular disease include increasing age, a low fiber diet, obesity,
lack of exercise, genetic predisposition, smoking, alcohol use, and certain medications
like steroids and NSAIDS.
A low-fiber diet can lead to hard stools and constipation, which can increase the pressure
in the colon, which can increase the risk of diverticular formation.
Let’s now walk through the main types of diverticular disease starting with diverticulosis
and its symptoms.
Remember we said diverticulosis is the presence of diverticula.
Diverticulosis does not normally present with symptoms.
Remember this form of diverticular disease is usually asymptomatic, unless it progresses
to another form of diverticular disease or complications develop.
If minor symptoms occur with diverticulosis, they typically include non-specific abdominal
issues such as bloating, constipation, diarrhea, and abdominal pain that is typically left-sided.
On physical exam, a patient with no symptoms may have a normal exam
Again diverticulosis is typically asymptomatic, but a patient with minor symptoms may experience
slight tenderness to palpation of their abdomen, rebound tenderness, or guarding.
Since diverticulosis typically does not have symptoms, it may be discovered incidentally.
This could be from CT imaging, routine colonoscopy, colorectal screening or flexible sigmoidoscopy
to name a few.
Now let’s look at the treatment of diverticulosis.
Given the lack of symptoms, diverticulosis is not treated unless there is progression
of disease, such as diverticulitis or diverticular hemorrhage, or if complications develop.
If diverticulosis is found incidentally, then lifestyle modifications may be recommended
including a high-fiber diet, smoking or alcohol cessation, exercise, and weight loss.
Diverticula can also become inflamed which is known as diverticulitis.
The cause of diverticulitis is not well understood.
But one theory is that it’s caused by stool entering a diverticulum and becoming entrapped.
The fecal stasis creates a build-up of pressure and bacteria, which can lead to inflammation
along with possible infection.
Symptoms of diverticulitis include left lower quadrant abdominal pain, nausea, vomiting,
fever, bloating, constipation, diarrhea, bloody stools, and rectal bleeding.
Some patients report worsening symptoms with eating and improve with defecation or passing
gas.
On physical exam, a patient with diverticulitis may have pain to palpation, guarding, or rebound
tenderness of the left lower quadrant or left iliac fossa.
Blood in the stool may be identified with a positive fecal occult blood test.
And pyrexia and tachycardia may be present as well.
Work up for diverticulitis typically involves a combination of blood and stool tests, along
with imaging or directly visualizing it.
Blood tests may include a complete blood count, chemistry, liver function tests, lipase, among
others depending on the case.
Diagnosis of diverticulitis is typically made through imaging or direct visualization.
This may include a CT scan of the abdomen and pelvis, or direct visualization from a
colonoscopy or flexible sigmoidoscopy.
Acute diverticulitis can be classified as simple or complicated.
Simple or uncomplicated diverticulitis refers to localized inflammation without associated
complications.
Simple diverticulitis may have milder symptoms than complicated and typically responds to
medical treatment without surgery.
Complicated diverticulitis refers to diverticulitis associated with complications and usually
requires surgery or more immediate management.
Complications of diverticulitis include abscess, obstruction, fistula, perforation, hemorrhage,
sepsis, or peritonitis.
The treatment of diverticulitis includes antibiotics, pain and symptom control, and possible fluid
resuscitation depending on the case.
Patients with uncomplicated diverticulitis may be able to be treated outpatient if stable
and tolerating feeds.
Patients with complicated diverticulitis may require inpatient treatment and possible surgical
intervention.
All patients will be recommended to make lifestyle adjustments such as a high-fiber diet, smoking
and alcohol cessation, exercise, and sufficient fluid intake.
Sometimes the diverticula can bleed, known as a diverticular hemorrhage.
A diverticular bleed is typically caused by a rupture of the vasa recta arteries in the
diverticulum.
Patients with a diverticular bleed may have large-volume painless rectal bleeding.
Diverticular hemorrhage may improve on its own in some patients but with others it may
require IV resuscitation and possible blood transfusion with packed red blood cells.
Diverticular hemorrhage may require a colonoscopy to identify the source.
Treatment with epinephrine injection or electrocauterization can be delivered to stop ongoing bleeding.
Complications of having diverticula include inflammation of the diverticula which is diverticulitis,
bleeding of the diverticula which is diverticular hemorrhage.
There can also be formation of an abscess or fistula.
Occasionally a bowel obstruction or bowel perforation can occur.
Peritonitis and sepsis are also potential complications.
Many of these complications are associated with diverticulitis more so than with diverticulosis.
Hopefully this helped you understand diverticular disease.
If you found the video useful, please share with others and hit that like button and leave
a comment.
Pass your classes and exams with the PDF notes and study guides for the video linked down below.
Save time studying by subscribing so you don’t miss out on future videos, notes, and study guides.
Thanks for watching and hope you check out future videos.