Differential Diagnosis for Proctitis

The differential diagnosis for proctitis, which is an inflammation of the rectum, can be categorized based on the likelihood and potential impact of missing a diagnosis. Here's a structured approach:

• Single Most Likely Diagnosis

  • Infectious Proctitis: This is often the most common cause, particularly in individuals with a history of anal intercourse or other forms of rectal trauma. It can be caused by a variety of pathogens including gonorrhea, chlamydia, herpes simplex, and others. The justification for this being the single most likely diagnosis lies in its prevalence and the common risk factors associated with sexual practices.

• Other Likely Diagnoses

  • Inflammatory Bowel Disease (IBD): Conditions like ulcerative proctitis, a form of ulcerative colitis limited to the rectum, are common causes of proctitis. The chronic nature of IBD and its potential for complications make it an important consideration.
  • Radiation Proctitis: This occurs in patients who have undergone radiation therapy for pelvic malignancies. The history of radiation exposure makes this a likely diagnosis in the appropriate context.
  • Chemical Proctitis: Caused by the use of certain suppositories or enemas, this form of proctitis is considered when there's a history of such use.

• Do Not Miss Diagnoses

  • Neoplastic Processes: Although less common, cancers such as rectal adenocarcinoma can present with symptoms of proctitis. Missing a diagnosis of cancer could have devastating consequences, making it crucial not to overlook this possibility.
  • Diverticulitis: While more commonly associated with the sigmoid colon, diverticulitis can occur in the rectum and present similarly to proctitis. Its potential for serious complications, such as abscess formation or perforation, necessitates consideration.
  • Ischemic Proctitis: This condition, resulting from reduced blood flow to the rectum, can be missed but has significant implications for patient management and outcome.

• Rare Diagnoses

  • Behçet's Disease: A form of vasculitis that can affect the gastrointestinal tract, including the rectum, and present with proctitis-like symptoms. Its rarity and systemic nature make it a less common but important consideration.
  • Amyloidosis: Involvement of the rectum can lead to proctitis symptoms. Given its rarity and the potential for systemic disease, amyloidosis is a diagnosis that, although unlikely, should be kept in mind.
  • Eosinophilic Proctitis: A rare condition characterized by eosinophilic infiltration of the rectal mucosa, often associated with eosinophilic gastrointestinal disorders. Its rarity and specific diagnostic criteria make it a less common diagnosis to consider.