When should ischemic colitis be suspected?
What are the key diagnostic tests for ischemic colitis, diverticulitis, acute appendicitis, colonic obstruction, and colonic pseudoobstruction?
How is diverticulitis medically managed? What are the indications for surgery in patients with diverticulitis?
What are the therapeutic options for colonic obstruction? for colonic pseudoobstruction?
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 $20 billion annually, which is likely to increase as the population ages. This chapter describes disorders of ischemic colitis, diverticulitis, acute appendicitis, colonic obstruction, and colonic pseudoobstruction. 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 162-1 describes key diagnostic tests and therapeutic options for important large bowel disorders, while Table 162-2 describes the colonoscopic findings.
Table 162-1 Key Diagnostic Tests and Therapies for Important Large Bowel Diseases in Hospitalized Patients |Favorite Table|Download (.pdf)
Table 162-1 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.
- Nuclear scintigraphy using radio-labelled erythrocytes – locates approximate site.
- Mesenteric angiography – can determine site and 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.
- Surgery – for ongoing bleeding refractory to colonoscopic or angiographic therapy.
- Colonoscopy – 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, impending peritonitis, and sepsis refractory to antibiotic therapy.
|Inflammatory bowel disease (IBD)|
- Blood tests – complete blood count, 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 disease.
- General therapy – bowel rest, intravenous hydration, correct electrolyte disorders.
- Medications – typically first corticosteroids, consider biologic anti-TNF alpha therapy, antibiotics for abscesses or fistulas.
- Surgery – for large or refractory abscesses, refractory toxic megacolon, severe disease refractory to medical therapy.
- 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 – ...