Infectious Colitis(Archived)

Excerpt

Colonic infection by bacteria, viruses, or parasites results in an inflammatory type of diarrhea, accounting for most cases presenting with acute diarrhea. These patients present with purulent, bloody, and mucoid loose bowel motions, fever, tenesmus, and abdominal pain. Common bacteria causing bacterial colitis include Campylobacter jejuni (C jejuni), Salmonella, Shigella, Escherichia coli (E coli), Yersinia enterocolitica, Clostridioides (formerly Clostridium) difficile (C diff), and Mycobacterium tuberculosis. Common causes of viral colitis include Norovirus, Rotavirus, Adenovirus, and Cytomegalovirus. Parasitic infestation, such as Entamoeba histolytica, a protozoan parasite, is capable of invading the colonic mucosa and causing colitis. Sexually transmitted infection affecting the rectum merits consideration during assessment. These diseases can occur in patients with human immunodeficiency virus (HIV) infection and men who have sex with men and may include Neisseria gonorrhoeae, Chlamydia trachomatis, herpes simplex virus, and Treponema pallidum.

Patients present with rectal symptoms that mimic inflammatory bowel disease, including rectal pain, tenesmus, bloody mucoid discharge, and urgency. Detailed medical history and identification of specific associated risks are essential in establishing the diagnosis. Stool microscopy culture and endoscopy are crucial to the diagnosis. However, stool culture helps diagnose less than 50% of patients with bacterial colitis, and endoscopic examinations usually reveal nonspecific pathological changes. Therefore, an approach is needed to evaluate and diagnose the cause of colitis and exclude non-infectious causes. This activity discusses current strategies to diagnose and manage infectious colitis, how to make a high index of suspicion based on clinical presentation, and how to use investigation methods to reach a final diagnosis. The etiology, epidemiology, pathophysiology, clinical presentation, evaluation, differential diagnosis, complications, and management of patients with infectious colitis are also reviewed.