Key Clinical Questions
When should you suspect and how do you evaluate ischemic colitis?
What medications should be avoided, if possible, in patients with suspected ischemic colitis, and in suspected colonic pseudo-obstruction?
How does the presentation of acute appendicitis in the older adult differ from that of younger individuals?
How do you evaluate and treat diverticulitis, colonic obstruction, and colonic pseudo-obstruction?
Large bowel disorders (LBD) impose a substantial burden on Americans, accounting for more than 1% of all inpatient admissions, contributing as comorbidities to other hospitalizations, and resulting in expenditures of more than 30 billion dollars annually, which is likely to increase as the population ages. This chapter describes disorders of ischemic colitis, diverticulitis, acute appendicitis, colonic obstruction, and colonic pseudo-obstruction. Other disorders, including lower gastrointestinal bleeding, inflammatory bowel diseases, tumors and cancer of the colon, and diarrhea are described in chapters dedicated to those disorders. Table 163-1 describes key diagnostic tests and therapeutic options for important large bowel disorders, while Table 163-2 describes the colonoscopic findings.
TABLE 163-1Key Diagnostic Tests and Therapies for Important Large Bowel Diseases in Hospitalized Patients ||Download (.pdf) TABLE 163-1 Key Diagnostic Tests and Therapies for Important Large Bowel Diseases in Hospitalized Patients
|Disease or Disorder ||Key Diagnostic Tests ||Major Therapeutic Options |
|Lower gastrointestinal bleeding || |
Colonoscopy—localizes site and determines etiology of bleeding.
Nuclear scintigraphy using radiolabeled erythrocytes—locates approximate site of bleeding.
Mesenteric angiography—can determine site & cause if lesion is actively bleeding.
CT enterography or capsule endoscopy—second-line tests if other tests are unrevealing.
Colonoscopy—injection, ablation, or mechanical therapy to stop the bleeding.
Angiography—intra-arterial vasopressin infusion or gelfoam or coil embolization to stop the bleeding.
Surgery—for ongoing bleeding refractory to colonoscopic or angiographic therapy.
|Ischemic colitis || |
Colonoscopy with colonoscopic biopsies—highly sensitive and specific.
Mesenteric angiography—can be diagnostic and therapeutic, test mandatory for involvement of major branches of superior mesenteric artery.
Abdominal computed tomography—important to exclude other conditions and often helps suggest the diagnosis.
Medical therapy—usually supportive, including bowel rest, intravenous fluids, antibiotic therapy, and reversal of precipitating factors.
Surgery—required for frankly infarcted bowel, colonic perforation, impending peritonitis, and sepsis refractory to antibiotic therapy.
|Inflammatory bowel disease (IBD) || |
Blood tests—complete blood count, erythrocyte sedimentation rate (ESR) or C-reactive protein.
Stool tests—for bacterial culture, fecal leukocytes, ova and parasites, C. difficile toxin.
Abdominal computed tomography—helpful to suggest IBD and to diagnose alternative conditions.
Colonoscopy—highly diagnostic in combination with colonic biopsies; examination of terminal ileum recommended for Crohn’s disease.
General therapy—bowel rest, intravenous hydration, correct electrolyte disorders.
Medications—typically first corticosteroids, consider biologic anti-tumor necrosis factor (TNF) alpha therapy, antibiotics for abscesses or fistulas.
Surgery—for large or refractory abscesses, refractory toxic megacolon, severe disease refractory to medical therapy.
|Diverticulitis || |
Abdominal computed tomography—radiologic test of choice for diagnosis and evaluating complications.
Colonoscopy—avoided in the setting of acute diverticulitis.
Medical therapy—bowel rest, intravenous antibiotics, intravenous hydration.
Percutaneous drainage—for large, walled-off abscess.
Surgery—multiple recurrent attacks, advanced Hinchey stage III ...