Proctitis

Proctitis is inflammation of the rectum. Causes include radiation, ischemia, infection, inflammatory bowel disease, and diversion of the fecal stream. Clinical features vary depending on the etiology but often include anorectal pain, tenesmus, pruritus, and rectal discharge or bleeding. Diagnosis involves a comprehensive clinical evaluation, including patient history and digital rectal examination. Laboratory studies such as rectal swabs for nucleic acid amplification testing (NAAT), stool studies, and serology are crucial for identifying infectious causes. Endoscopy (e.g., proctoscopy or colonoscopy) with biopsy is essential for direct visualization of the rectal mucosa, histopathological examination, and to rule out other pathologies. Imaging studies such as CT or MRI of the abdomen may be considered to exclude malignancy or to evaluate for complications (e.g., strictures or fistulas). Management is tailored to the underlying cause.

• The diagnostic approach is guided by the clinical picture.
• Obtain a comprehensive patient history, including a detailed sexual history.
• Perform a physical examination, including digital rectal examination. ^[1]
• All patients with acute proctitis should be evaluated for infectious proctitis regardless of sexual history. ^[9]
• Diagnosis is confirmed with endoscopy.

See "Chronic radiation proctitis" and "Acute radiation proctitis" for details.

Epidemiology

• Occurs in 5% of patients with ischemic colitis ^[5]
• Spontaneous ischemic proctitis is very rare (< 2% of all cases of ischemic colitis) ^[5]

Etiology ^[5]

• Ischemic proctitis typically occurs following a sudden loss of blood flow resulting from, e.g.:
  • Vascular intervention or surgery
  • Radiotherapy
  • Hypotensive shock
• Risk factors include:
  • Atherosclerotic disease
  • Older age

Clinical features ^[5]

• Rectal bleeding
• Fecal urgency
• Tenesmus
• Rectal mucus discharge
• Fecal incontinence
• Constipation
• Incomplete defecation

Diagnosis ^[5]

• Colonoscopy
• CT abdomen
• See also "Diagnostics" in "Colon ischemia" for further details.

Treatment ^[5]

• Consider broad-spectrum antibiotics.
• Consider surgical resection.
• See also "Treatment" in "Colon ischemia" for further details.

Etiology ^[6]

• STIs
  • Most common causative organisms ^[10]
    • N. gonorrhoeae
    • C. trachomatis: including lymphogranuloma venereum (LGV) and non-LGV
    • HSV
    • Treponema pallidum
  • Other causative organisms
    • Mycoplasma genitalium
    • Monkeypox virus
• Non-STIs
  • Bacterial: campylobacter, shigella
  • Cytomegalovirus colitis

Transmission of STIs causing proctitis is typically through receptive anal sexual activity. Populations at risk for infectious proctitis include men who have sex with men and people living with HIV. ^[6]

Clinical features

General features ^[10]

• Rectal bleeding
• Rectal mucus discharge
• Pain
• Tenesmus
• Fecal urgency
• Diarrhea
• Constipation
• Fever may be present.

Disease-specific features ^[6]

• HSV
  • Characteristic: painful perianal vesicles or ulcers
  • Sacral paresthesia may also occur.
• Primary syphilis: Perianal or genital ulcers (chancre) may be seen.
• LGV: Painful inguinal adenopathy (buboes) is a typical finding.
• Mpox: A prodromal phase with fever and lymphadenopathy is often followed by a skin eruption.

Infectious proctitis is sometimes asymptomatic, particularly in N. gonorrhoeae and non-LGV C. trachomatis infections. ^{[10] [6]}

Diagnosis

Laboratory studies ^[6]

• Anal swab for NAAT ^[10]
  • N. gonorrhoeae
  • C. trachomatis
  • HSV
  • Monkeypox virus (from skin or anorectal lesion)
  • M. genitalium (indicated in symptomatic proctitis after excluding other common causes)
• Stool studies
  • Stool microscopy for ova, cysts, and parasites
  • Stool culture
• Serology
  • Syphilis (nontreponemal and treponemal tests)
  • Screen for other potential STIs (e.g., HIV, hepatitis B, hepatitis C).

Sigmoidoscopy with rectal biopsy ^[6]

• Macroscopic findings include erythema, erosions, ulcers, and/or vesicles.
• Biopsy and lesion swabs for NAAT

Infectious proctitis and inflammatory bowel disease share overlapping clinical, endoscopic, and histological features, which can make differentiation challenging. ^[6]

Management ^[6]

• General principles
  • Provide patients with clear information about their condition, including transmission, complications, and prevention.
  • Advise patients to abstain from sexual activity until symptoms resolve, test results for the specific pathogen are negative, and 7 days have passed after completing treatment.
  • Provide STI management of sexual partners.
  • Report notifiable diseases (e.g., gonorrhoea, chlamydia, syphilis, HIV, mpox) to public health authorities.
• Empiric therapy
  • Provide empiric management of STIs with antibiotics for severe symptoms while waiting for microbiological results.
  • Consider empiric treatment for HSV in patients with painful ulcers, especially those with HIV.
• Specific therapy
  • Guided by the underlying cause
  • See also "Treatment for STIs" and "Treatment of gastroenteritis."

Definition

IBD-related proctitis is rectal inflammation due to ulcerative colitis (most common) or Crohn disease.

Proctitis due to Crohn disease is very rare but can be severe. ^[5]

Clinical features ^[7]

• Rectal bleeding
• Fecal urgency
• Tenesmus
• Rectal mucus discharge
• Fecal incontinence
• Constipation
• Incomplete defecation

Onset is typically insidious and the clinical course is often unpredictable, with alternating periods of exacerbation and remission. ^[7][10]

Diagnosis

• Laboratory studies ^[10][11]
  • Elevated inflammatory markers
  • Stool: elevated fecal calprotectin
  • See also "Diagnosis" in "Ulcerative colitis."
• Colonoscopy and biopsy ^[7][11]
  • Inflammation begins at the anal verge and continuously extends in a proximal direction. ^[10]
  • A sharp demarcation between inflamed and normal mucosa is often visible.
• Imaging (e.g., CT or MRI abdomen): for suspected Crohn disease

Management

• Pharmacological treatment (e.g., glucocorticoids, biologics, immunomodulators)
• Surgery: for severe complications (e.g., bowel obstruction)
• See also "Treatment" in "Ulcerative colitis."

Definition ^[7]

Diversion proctitis is a type of proctitis that occurs following surgical diversion of the fecal stream (e.g., colostomy or ileostomy).

Etiology ^[7]

While the etiology of diversion proctitis is not fully understood, the following are likely contributing factors:

• Short-chain fatty acid (SCFA) deficiency
  • SCFAs (e.g., acetate, propionate, butyrate) are the main metabolic fuel for colonocytes.
  • Produced by anaerobic bacterial fermentation of dietary carbohydrates and therefore deficient in the diverted section
• Gut microbiome changes: alterations in the gut flora in the excluded rectum, with a significant reduction in obligate anaerobes

Clinical features ^[7]

Symptoms occur 3–36 months after surgical diversion and include the following, although some patients are asymptomatic.

• Rectal mucus discharge
• Rectal bleeding
• Tenesmus
• Abdominal or pelvic pain
• Low-grade fever

Diagnosis ^[7]

Evaluate for diversion proctitis in any patient with a history of fecal diversion and clinical features of diversion proctitis.

• Endoscopy: Findings may be similar to active ulcerative proctitis.
• Biopsy: Findings include diffuse inflammation.

Management ^[7]

• Surgical restoration of intestinal continuity (e.g., early reanastomosis) is preferred.
• SCFA enemas are considered if surgical intervention is not feasible.

Symptoms typically resolve after restoration of gastrointestinal continuity. ^[7]

Complications ^[7]

• Distal rectal or anal stricture
• Complete occlusion of the rectum