Perianal Crohn's Disease

The cause is the same immune-driven inflammation that causes Crohn's disease elsewhere. Deep ulcers in the rectum or anal canal can tunnel through the bowel wall and form fistulas, and trapped infection forms abscesses. Smoking is linked with worse Crohn's disease and is worth stopping.

Perianal disease affects a meaningful share of people with Crohn's disease at some point, and is more frequent when the rectum is inflamed. It can be the first sign of Crohn's disease in some people.

Diagnosis involves an examination of the area, sometimes under anaesthesia for accuracy. MRI of the pelvis is the best imaging test to map fistulas and abscesses. Endoanal ultrasound can also help. A colonoscopy checks whether Crohn's disease is active in the rectum and bowel, because treatment depends on this.

Gentle daily care and healthy habits help symptoms and healing.

• Keep the area clean with water and gentle, unscented cleansing; pat dry rather than rubbing.

• Warm sitz baths (sitting in shallow warm water) can ease pain.

• Stop smoking; it makes Crohn's disease worse.

• Use pads for drainage, and avoid tight clothes.

• Do not squeeze or try to drain a swelling yourself.

No diet cures perianal disease, but avoiding both diarrhea and constipation reduces irritation.

• Aim for soft, well-formed stools; adjust fibre according to what your team advises.

• Drink enough fluids.

• Keep a food diary to notice foods that trigger loose stools.

• Ask for a dietitian review if you are losing weight or avoiding many foods.

Medicines aim to control Crohn's inflammation and help fistulas heal.

• Biologic medicines (anti-TNF drugs and others) are often the main treatment for fistulas; your specialist chooses which.

• Antibiotics may be used for infection or as short-term support.

• Immunomodulators may be added to biologics in some cases.

• Pain relief and creams for local comfort can be prescribed.

• Do not stop treatment without discussing it, even when symptoms improve.

Your doctor decides which medicine and for how long.

Surgery treats infection and protects the sphincter muscles that control stool.

• Abscesses are drained surgically; this brings relief quickly.

• A seton (a soft thread placed through the fistula) keeps it draining and prevents repeat abscesses while medicines work.

• Once inflammation is controlled, selected fistulas may be closed with flaps, plugs or stem-cell injection.

• Dilation can help narrowing; a temporary stoma may be considered for severe disease to let tissue heal.

• Your surgeon will aim to protect continence, so stool control is preserved as much as possible.

Current guidelines support a combined approach: control any abscess surgically, then treat the underlying inflammation with medicines, often biologic therapy, sometimes with antibiotics as a bridge. Research on stem-cell injections for complex fistulas is ongoing, and availability varies.

Perianal Crohn's disease is often long-lasting, with periods of improvement and relapse. Many fistulas improve or close with modern combined treatment, though some persist and need long-term management. Early specialist care lowers the risk of complications and the need for major surgery.

• What type of fistula or abscess do I have, and what does the MRI show?

• Which medicine is best for my fistula, and how long before it works?

• Do I need a seton or other surgery?

• Will treatment affect my ability to control stool?

• Does this affect plans for pregnancy or childbirth?

This guide comes from the Saudi Gastroenterology Association (SGA) patient library, prepared by the Approved for publication by SGA; individual clinician review is ongoing. Last reviewed: 2026-04-24. It is for education and does not replace your doctor's advice.