Topical Therapies (Rectal 5-ASA & Steroids)

Topical therapies deliver medicine directly into the rectum and lower colon using suppositories, foams, or enemas. They are especially helpful for ulcerative colitis that is limited to the rectum or left side of the colon. Used correctly, rectal 5-aminosalicylic acid (5-ASA, mesalamine) and rectal steroids can control bleeding and urgency quickly, often with fewer whole-body side effects than oral steroids.

Key Takeaways

• Rectal medicines put drug right where inflammation is, which can make them very effective for proctitis and left-sided ulcerative colitis. (pubmed.ncbi.nlm.nih.gov)

• Guidelines recommend rectal 5-ASA as first choice for mild to moderate ulcerative proctitis, with enemas plus oral 5-ASA for left-sided disease. (journals.lww.com)

• Rectal steroids (such as hydrocortisone or budesonide) are usually short-term options when rectal 5-ASA is not enough or not tolerated. (journals.lww.com)

• Suppositories mainly treat the rectum, foams spread through the rectum and lower left colon, and enemas reach higher into the left colon. (aafp.org)

• Correct timing and technique improve comfort and medicine contact time and help reduce leakage and cramping.

• Serious side effects are uncommon, but heavy bleeding, severe pain, fever, or allergic symptoms need urgent medical care. (webmd.com)

What are topical rectal therapies?

Topical rectal therapies are medicines placed into the rectum so they can coat the rectum and lower colon from the inside. They are given as:

• Suppositories (small solid inserts)

• Foams (puffs of medicated foam)

• Enemas (liquid in a squeeze bottle or bag)

Two main drug types are used:

• 5-aminosalicylic acid (5-ASA or mesalamine), an anti-inflammatory medicine that works on the lining of the gut

• Corticosteroids (such as hydrocortisone or budesonide), stronger anti-inflammatory drugs used for short-term control

Because these medicines act mostly where they are placed, they can reduce rectal bleeding, urgency, and mucus with less whole-body exposure than many oral steroids. (pubmed.ncbi.nlm.nih.gov)

When are rectal treatments used?

Rectal therapies are best studied in ulcerative colitis, especially when disease is limited to:

• Ulcerative proctitis (rectum only)

• Proctosigmoiditis (rectum and sigmoid colon)

• Left-sided colitis (up to the splenic flexure) (aafp.org)

Major North American and European guidelines:

• Recommend rectal 5-ASA suppositories for mildly to moderately active ulcerative proctitis. (journals.lww.com)

• Recommend rectal 5-ASA enemas plus oral 5-ASA for left-sided or more extensive mild to moderate ulcerative colitis, because the combination is more effective than oral medicine alone. (mdedge.com)

• Prefer rectal 5-ASA over rectal steroids as first choice for induction of remission in distal disease. (journals.lww.com)

Topical steroids are suggested when symptoms persist despite rectal 5-ASA, or when 5-ASA cannot be used. (journals.lww.com)

In Crohn’s disease, rectal therapies play a smaller role. They may be considered when inflammation is limited to the rectum or very distal colon, but most evidence for benefit comes from ulcerative colitis, not Crohn’s. (pubmed.ncbi.nlm.nih.gov)

Forms of rectal therapy and what they reach

A care team will usually match the form to how far inflammation extends on scope.

How to use suppositories, foams, and enemas

General preparation

For any rectal medicine:

• Try to empty the bowel shortly beforehand.

• Wash hands and check the product name and expiration date.

• If possible, use the medicine at bedtime, so it can stay in place longer. (drugs.com)

Always follow the specific instructions on the package and from the prescriber.

Using suppositories

1. If the suppository is soft, some products allow brief cooling in a refrigerator.

2. Remove the wrapper.

3. Lie on the left side with knees slightly bent, or stand with one leg raised.

4. Gently insert the pointed end into the rectum, past the sphincter muscle.

5. Stay lying on the side for several minutes and avoid using the toilet so the medicine can melt and coat the rectum.

Many mesalamine suppositories are used once daily at bedtime for several weeks, then sometimes less often for maintenance, depending on the plan. (drugs.com)

Using foam products

1. Attach the applicator as described in the package insert.

2. Shake or prime if the instructions say to do so.

3. Lie on the left side or stand with one leg raised.

4. Gently insert the applicator, press to release the foam, then remove it.

5. Stay lying for a short time and try not to pass gas right away, so the foam can spread. (pubmed.ncbi.nlm.nih.gov)

Foam often feels lighter and is easier to hold than liquid, which many people prefer.

Using liquid enemas

1. Shake the bottle if instructed.

2. Lie on the left side with the right knee bent.

3. Lubricate the nozzle tip if needed.

4. Insert the tip gently into the rectum and squeeze the bottle steadily until most of the liquid is inside.

5. Withdraw the nozzle, stay lying for at least 15 minutes, and aim to retain the enema for several hours or overnight if possible. (drugs.com)

Small leaks are common at first and usually improve with practice.

Rectal 5-ASA vs rectal steroids

Rectal 5-ASA (mesalamine)

• First-line for mild to moderate ulcerative proctitis and distal colitis. (journals.lww.com)

• Trials of mesalamine suppositories show high remission rates within about 4 weeks in active distal disease. (pubmed.ncbi.nlm.nih.gov)

• Rectal 5-ASA is often more effective than oral 5-ASA alone for distal disease and is preferred over rectal steroids for induction. (pubmed.ncbi.nlm.nih.gov)

• Maintenance studies show regular mesalamine suppositories can reduce relapses of distal ulcerative colitis over 6 to 12 months. (pubmed.ncbi.nlm.nih.gov)

Because systemic levels are low, serious whole-body side effects are uncommon, though rare kidney and allergic problems can still occur. (webmd.com)

Rectal steroids (hydrocortisone, budesonide, others)

• Used when rectal 5-ASA is not tolerated or does not control symptoms. (journals.lww.com)

• Hydrocortisone foams and enemas and budesonide foams or enemas can induce remission in distal ulcerative colitis and proctitis. (pubmed.ncbi.nlm.nih.gov)

• Budesonide foam spreads through the rectum and sigmoid colon with low systemic absorption and generally normal cortisol levels over 4 to 8 weeks. (pubmed.ncbi.nlm.nih.gov)

Guidelines still prefer rectal 5-ASA over rectal steroids for initial treatment, but recognize topical steroids as useful add-on or second-line options. (journals.lww.com)

Side effects and safety

Common, usually mild effects

For both 5-ASA and steroid rectal products, people may notice:

• Local burning, fullness, or mild cramping

• A sense of urgency right after insertion

• Small leaks or staining of underwear or pads (my.clevelandclinic.org)

These usually ease as the person becomes used to the medicine and timing.

Less common but important risks

Rectal 5-ASA:

• Allergic reactions, sometimes with rash, fever, or worsening diarrhea

• Rare serious skin reactions or inflammation of the heart or kidneys, including interstitial nephritis and kidney stones (webmd.com)

Providers often check kidney blood tests, especially when someone also takes oral mesalamine.

Rectal steroids:

• With short courses, systemic effects are usually small, but with higher doses or longer use, there can be:

• Weight gain, fluid retention, higher blood pressure

• Increased blood sugar, bone thinning, mood changes

• Lowered resistance to infection, adrenal suppression (drugs.com)

For that reason, steroid rectal products are generally used for limited periods, and stopping after long use may need a taper plan from the prescriber.

When to contact the care team

Anyone using rectal 5-ASA or steroids should seek medical advice promptly if they notice:

• Heavy or increasing rectal bleeding

• Sudden severe abdominal pain, bloating, or inability to pass gas or stool

• Fever, chills, or feeling very unwell

• New chest pain, shortness of breath, or swelling of the face or throat

• Dark urine, yellowing of skin or eyes, or marked drop in urine amount

• Clear worsening of colitis symptoms soon after every dose of mesalamine (webmd.com)

Treatment choices and dose schedules always need to be set or changed by the prescribing clinician, based on disease location, severity, and other medicines.

FAQs

Can rectal medicines replace oral medicines?

For disease limited to the rectum, a rectal 5-ASA suppository alone is often enough for both induction and maintenance. (journals.lww.com)
When more of the colon is involved, rectal therapy usually adds to oral medicines rather than replacing them.

How long before rectal therapy starts helping?

Some studies show less bleeding within a few days of starting mesalamine suppositories, but full benefit often takes 3 to 6 weeks. (pubmed.ncbi.nlm.nih.gov)
Steroid foams and enemas can also improve urgency and bleeding within the first weeks.

What if using rectal treatment feels embarrassing or difficult?

This reaction is very common. Many people find it easier after a short learning period, especially when doses are given at night and routines are predictable.
If the volume or position is too hard to manage, a care team can often suggest a different form, such as switching from an enema to foam or from foam to a suppository, depending on disease location. (aafp.org)