AssessmentsDiverticular disease: Clinical practice
USMLE® Step 1 style questions USMLE
USMLE® Step 2 style questions USMLE
A 64-year-old woman comes to the emergency department because of cramping left lower quadrant abdominal pain for the past day. She has a past medical history of chronic constipation for which she takes polyethylene glycol. She says that her most recent bowel movement contained a small amount of blood. Her temperature is 38.2°C (100.8°F), pulse is 88/min, respirations are 18/min, and blood pressure is 155/80 mm Hg. Physical examination shows point tenderness at the left lower quadrant with localized guarding. What is the most likely cause of her symptoms?
Content Reviewers:Rishi Desai, MD, MPH
Diverticula are small outpouchings that form along the walls of a hollow structure.
Diverticula usually form at weak spots along the wall, like where a blood vessel penetrates the muscle layer of the intestine.
The second is a false or pseudodiverticula which is where only the mucosa and submucosa slide through the intestinal wall, and these end up being more common.
Risk factors for diverticula, including eating a high-fat, red meat diet that’s low in fiber.
Sometimes it’s asymptomatic, and diverticulosis is diagnosed incidentally during an abdominal scan or a colonoscopy that was needed for another reason.
When diverticulosis is symptomatic, it’s called diverticular disease.
Typically diverticular disease causes some abdominal pain and a CT-scan usually shows some bowel thickening. But at this stage, treatment is mainly encouraging a high-fiber diet with grains and vegetables.
But at any point diverticulosis can cause complications.
One complication is bleeding due to weakening and breaking of blood vessels near a diverticula.
When there’s bleeding, depending on the severity, lab work and resuscitation are usually done.
Labs include a CBC to look for signs of anemia and assess the platelet count.
To see if the bleeding is coming from the upper GI tract, gastric lavage- which is where fluids are placed in the stomach and then suctioned back out to look for signs of bleeding - and an upper endoscopy can be done as well.
After that, a colonoscopy is performed within 24 hours of presentation to identify and stop the source of the bleeding using endoscopic therapy.
One option is to inject the site of bleeding with epinephrine.
Alternatively, the vessel can be treated with thermocoagulation using cautery probes.
Cautery probes use an electrical current to melt a tiny blood vessel and seal it shut to stop the bleeding.
If the source of bleeding isn’t identified using colonoscopy or if the bleeding can’t be stopped endoscopically, then angiography can be used. That’s where a contrast agent is injected into a blood vessel and then imaging is done to identify the location of any active bleeding. Unfortunately, it may miss intermittent bleeds.
Now, if a source of active bleeding is found through angiography, then vasoconstricting medication like vasopressin can be given, or the bleeding vessel can be embolized.
If neither colonoscopy nor angiography are able to identify and stop the bleeding, then surgery is required and often a segmental colectomy is done. That’s where part of the colon is removed.
Another complication of diverticulosis is acute diverticulitis - which is an infection of the diverticula.
Typically it starts when there’s increased pressure in the lumen of the intestines or food impaction in the diverticulum that leads to micro-perforations in the diverticula.
The bacteria in the lumen of the gut dive into these microperforations, and cause infection within the wall of the diverticula.
Acute diverticulitis can also lead to the formation of an abscess within the inflamed diverticula.
The symptoms of a diverticular abscess are about the same as the symptoms of acute diverticulitis, but usually with an abscess, the oral antibiotics used for acute diverticulitis don’t work as well, and the fever and other symptoms persist.
If the inflamed diverticula is near another organ or skin surface it can also create a fistula, and this most commonly occurs with the bladder. When that happens it’s called a colovesical fistula.
In a colovesical fistula there can be dysuria, pneumaturia -which is the passage of gas in the urine, as well as fecaluria- which is the passing of stool in the urine. Yep, it’s pretty hard to forget that set of symptoms!
Acute diverticulitis can also lead to a partial obstruction of the colon due to the inflammation, and that can cause abdominal pain, distention, and vomiting.
The lab work for acute diverticulitis and its complications include a CBC, looking for leukocytosis, along with electrolytes- especially if there’s dehydration due to diarrhea- and urine analysis, which can show sterile pyuria due to inflammation near the bladder.
In addition, stool microscopy to search for ova and parasites along with testing for C.difficile toxin are done if those are suspected.
Acute diverticulitis is usually diagnosed with a CT scan with contrast of the abdomen and pelvis, which will show colonic diverticula, with localized bowel wall thickening, and increased density in the surrounding fat.
The CT can also identify the presence of an abscess or fistula.
If there’s an abscess, there will be a fluid collection surrounded by an inflamed diverticula.
In individuals with perforation and peritonitis, the CT shows free air seen within the peritoneum.
A colonoscopy should not be performed in acute diverticulitis, because it increases the risk for perforation and subsequent peritonitis.
Treatment of acute diverticulitis can differ based on the presence of complications.
In individuals that are allergic to Metronidazole, Moxifloxacin alone can be used instead.