Anorectal disorders are a group of conditions that affect the anus and rectum. They can cause discomfort, bleeding, pain, and difficulty with bowel movements. Common anorectal disorders include haemorrhoids, anal fissures, anorectal abscesses, fistulas, and rectal prolapse. Early diagnosis and management are important to prevent complications and improve quality of life.
Causes
- Straining during bowel movements due to constipation or diarrhoea
- Chronic diseases such as inflammatory bowel disease (IBD)
- Infections including sexually transmitted infections (STIs)
- Trauma to the anorectal area (e.g., childbirth, surgery)
- Tumours (benign or malignant)
- Congenital abnormalities in some cases
Pathophysiology
Anorectal disorders often result from increased pressure within the anal canal, trauma to the lining of the anus or rectum, infection of glands or tissues, or weakening of supporting structures. For example, haemorrhoids occur when the veins around the anus become swollen and inflamed due to pressure. An anal fissure results from a tear in the lining, leading to a cycle of pain and sphincter spasm. Fistulas form from infected glands creating abnormal channels to the skin.
Signs and Symptoms
- Pain during or after bowel movements
- Bright red rectal bleeding (on toilet paper or in the toilet)
- Itching, irritation, or burning sensation around the anus
- Lump or swelling at the anal margin
- Pus discharge in cases of abscesses or fistulas
- Difficulty passing stool or feeling of incomplete emptying
- Protrusion of tissue through the anus in prolapse
Risk Factors
- Chronic constipation or diarrhoea
- Pregnancy and vaginal delivery
- Obesity
- Sedentary lifestyle
- Older age
- Poor bowel habits (e.g., prolonged sitting on the toilet)
- Immunosuppression increasing risk of infections
- History of anal surgery or trauma
Investigation
- Clinical examination: Inspection, digital rectal examination (DRE), anoscopy or proctoscopy
- FBC (Full Blood Count): To check for anaemia if significant bleeding occurs
- Stool tests: To exclude infection or inflammatory markers
- Pelvic MRI or Endoanal Ultrasound: Especially useful for complex fistulas
- Flexible sigmoidoscopy or colonoscopy: Recommended if malignancy or inflammatory bowel disease is suspected
- CT scan: If abscess or deep infection is suspected
Management
1. Non-Pharmacological Management
- Dietary modification: High-fibre diet to soften stools and prevent straining
- Adequate hydration: Drinking plenty of fluids to maintain soft stools
- Sitz baths: Sitting in warm water to relieve pain and promote healing, especially for fissures or haemorrhoids
- Improved bowel habits: Avoid prolonged sitting or straining during bowel movements
2. Pharmacological Management
- Topical treatments: Local anaesthetics, corticosteroids for inflammation, and vasoconstrictors for haemorrhoids
- Oral laxatives: Bulk-forming agents like ispaghula husk or osmotic laxatives for constipation
- Analgesics: Paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) for pain relief
- Antibiotics: For anorectal abscesses or infected fistulas
3. Surgical Management
- Haemorrhoidectomy: Surgical removal of large or thrombosed haemorrhoids
- Lateral internal sphincterotomy: Procedure for chronic anal fissures not responding to medical therapy
- Incision and drainage: For anorectal abscesses
- Fistulotomy: Surgery to open and heal anorectal fistulas
- Rectopexy: Surgical correction for rectal prolapse
Complications
- Chronic pain and discomfort
- Infection and abscess formation
- Recurrence of haemorrhoids, fissures, or fistulas
- Fecal incontinence after surgery or extensive disease
- Stricture formation (narrowing of the anal canal)
- Malignancy in untreated or chronic fistula-in-ano (especially in Crohn’s disease)
References
- National Institute for Health and Care Excellence (NICE) Guidelines: Haemorrhoids management (NG44), Anal fissure (CG37)
- Royal College of Surgeons (RCS) Clinical Guidance for Anorectal Disorders
- British Society of Gastroenterology (BSG) Guidelines on Lower GI Disorders
- General Medical Council (GMC) Good Medical Practice 2024