Diverticulitis: Clinical sciences

Diverticulitis is inflammation of a diverticulum, which is a small pouch protruding from the bowel wall. Be sure not to mix it up with diverticulosis, which is the presence of multiple diverticula that develop because of a high-fat and low-fiber diet. However, even though it is commonly believed, eating things like seeds, nuts, and popcorn does not increase the risk of developing diverticulosis or diverticulitis.

Now, diverticulitis occurs when increased bowel pressure, from things like food or stool, causes a tiny hole or micro perforation in the diverticulum wall. This allows bacteria from the lumen to seed the diverticulum, which results in infection and inflammation. Diverticulitis can be classified as uncomplicated or complicated diverticulitis. In uncomplicated diverticulitis, only the diverticulum is inflamed, while in complicated diverticulitis, perforation, abscess, or fistula might be present as well.

Alright, when a patient presents with signs and symptoms of diverticulitis, you should first perform an ABCDE assessment. The individual can be  unstable if septic shock develops, so you should stabilize their airway, breathing, and circulation. This means that you may need to intubate the patient, establish IV access, or administer fluids before continuing with your assessment.

However, if the patient is stable, the next step is to obtain a focused history and physical examination. History typically reveals abdominal pain, most often in the left lower quadrant, and sometimes symptoms like fever, nausea, vomiting, and recent changes in bowel habits, such as constipation or diarrhea.

Physical examination usually reveals abdominal distention and tenderness in the affected area, most commonly in the left lower quadrant. There can also be elevated temperature. The most dangerous signs to look for are guarding, rigidity, and rebound pain, which point to peritonitis.

A rectal examination may reveal a palpable mass within the distal sigmoid colon. The stool may also be positive for occult blood.

An important thing to remember is that rectal bleeding is more commonly associated with diverticulosis than diverticulitis. However, unlike diverticulitis, diverticulosis is usually asymptomatic and found incidentally.

Alright, as for the labs, check for leukocytosis, elevated CRP, and lactate. These are not specific for acute diverticulitis, but may support the diagnosis.

In terms of imaging, order a CT scan of the abdomen and pelvis with oral and IV contrast.

In uncomplicated diverticulitis, CT examination reveals diverticula which are outpouchings of the bowel wall, focal thickening of the bowel wall, and pericolonic fat stranding in the region of the inflamed diverticula.

In complicated diverticulitis, you might also see an associated abscess, pneumoperitoneum, or fistula. For example,  air bubbles within the bladder might be a sign of a colovesical fistula.