Inflammatory bowel disease (ulcerative colitis): Clinical sciences

Inflammatory bowel disease, or IBD, is a condition characterized by chronic gastrointestinal tract inflammation. It can be subdivided into Ulcerative Colitis and Crohn Disease.

Ulcerative Colitis, or UC, primarily affects the colon and is characterized by continuous ulcerations of the mucosa and submucosa, which may lead to abdominal pain, bloody diarrhea, and tenesmus. Management is based on the severity of disease and they can be categorized as mild to moderate, moderate to severe, or acute severe.

Now, when assessing an individual with suspected ulcerative colitis, you should first perform an ABCDE assessment to determine if they are stable or unstable. Unstable individuals might present with signs of shock, like tachycardia and hypotension, so you might have to secure their airway, breathing, and circulation before further workup. Unstable patients may also have signs of complications like toxic megacolon, perforated colon, or severe refractory hemorrhage. These patients should be hospitalized, and given intravenous fluids and antibiotics.

Once they are stable, you should find out what caused the instability. If the patient presents with pallor and profuse rectal bleeding, consider anemia and hypovolemic shock due to severe refractory hemorrhage. In this situation, begin systemic corticosteroids and transfuse blood products. If the abdomen is distended or firm, consider toxic megacolon. An X-ray might reveal an enlarged colon and possibly signs of perforation, like pneumoperitoneum.

These patients should also have stool studies to rule out C. difficile infection. A high yield fact to keep in mind about unstable patients is that you should avoid colonoscopy because there is a high risk of colon perforation. If an unstable patient has evidence of severe refractory hemorrhage, toxic megacolon, or perforated viscus, you can consult surgery for possible colectomy.

Now, when it comes to stable individuals, the first step is to obtain a focused history and physical exam. History typically reveals diffuse or periumbilical crampy abdominal pain, bloody diarrhea, tenesmus, and fecal urgency. Some patients report extra-intestinal symptoms, like eye pain, joint pain, and rashes.

Physical exam usually reveals an abdomen that’s tender to palpation. Additionally, there might be extra-intestinal manifestations, such as eye findings like uveitis and episcleritis; skin findings like tender red spots that indicate erythema nodosum and painful ulcerations associated with pyoderma gangrenosum; or even jaundice that might point to Primary Sclerosing Cholangitis. Finally, the rectal exam might reveal bright red blood and discomfort on palpation.

Now, to differentiate IBD from other diagnoses with similar presentations, such as Irritable Bowel Syndrome or IBS and C.difficile colitis, you should obtain stool laboratory studies. Fecal calprotectin is a marker of colon inflammation. Since IBS does not cause colon inflammation, a positive fecal calprotectin would increase your suspicion for IBD. Similarly, negative stool studies for pathogens help rule out infectious etiologies like C.difficile colitis. Next, you should check blood work, which may reveal anemia and elevated inflammatory markers such as CRP and ESR.

If the H&P, imaging, and lab findings suggest IBD, the next step is to confirm the diagnosis with a colonoscopy with biopsies. On colonoscopy, you may observe erythema, a decreased or absent vascular pattern, friability, and ulcerations in a continuous pattern.

UC usually starts in the rectum, which is called proctitis, and typically progresses to the splenic flexure, which is referred to as left-sided colitis. Sometimes it can extend beyond the splenic flexure, which is then called extensive colitis. Some individuals develop inflammation just beyond the ileocecal valve, called backwash ileitis, so don’t forget to visualize the ileum during colonoscopy.

Biopsy of the ileum with histopathologic evaluation will help differentiate UC from Crohn Disease, in which the ileum is the most commonly affected segment of the GI tract. Typical histopathologic findings of UC on biopsy include mucosal and submucosal chronic inflammation, erosions, ulcerations, and crypt abscesses.

After you confirm the diagnosis of UC with colonoscopy, you should determine the severity of the disease based on signs and symptoms like frequency of stools per day, amount of blood in the stool, the presence of cramps and tenesmus, amount of weight loss, and colonoscopy findings. Using these findings, UC can be broken down into three categories: mild to moderate, moderate to severe, and acute severe ulcerative colitis.