Topical Therapies (Rectal 5-ASA & Steroids)

Topical therapies deliver medicine directly to the rectum and left colon. They come as suppositories, foams, and enemas. These options work best for ulcerative colitis that is limited to the rectum or the left side of the colon. They can also be added to oral therapy to control urgency and bleeding from the bottom. They act locally, and most have few whole‑body side effects. (pmc.ncbi.nlm.nih.gov)

Key takeaways

• Match the form to the location: suppository for rectum, foam for rectum to sigmoid, enema for rectum to splenic flexure. (pubmed.ncbi.nlm.nih.gov)

• Rectal mesalamine (5‑ASA) is first‑line for proctitis or proctosigmoiditis and is preferred over rectal steroids. (pmc.ncbi.nlm.nih.gov)

• Add rectal mesalamine to oral 5‑ASA for left‑sided or extensive disease when symptoms persist. (gastro.org)

• Use rectal steroids if mesalamine is not tolerated or ineffective, but do not use steroids for maintenance. (pmc.ncbi.nlm.nih.gov)

• Typical courses: mesalamine 3 to 6 weeks; budesonide foam 6 weeks. For maintenance in proctitis, mesalamine suppositories can be used daily or a few times per week. (drugs.com)

What are rectal 5‑ASA and rectal steroids

• 5‑aminosalicylic acid (5‑ASA, mesalamine) calms inflammation in the lining of the rectum and colon. It is effective for mild to moderate disease limited to the lower bowel. Forms include 1 gram suppositories and 4 gram enemas. (pmc.ncbi.nlm.nih.gov)

• Rectal corticosteroids reduce inflammation quickly. Budesonide foam has low systemic exposure. Hydrocortisone enemas can be absorbed more and may cause steroid effects with prolonged use. These are used for induction, not maintenance. (drugs.com)

When are topical therapies used

• Ulcerative proctitis or proctosigmoiditis: start with rectal mesalamine. Suppositories are best for disease limited to the rectum. Enemas reach higher when the sigmoid colon is inflamed. (pmc.ncbi.nlm.nih.gov)

• Left‑sided colitis: use a mesalamine enema. If oral 5‑ASA is already used, add the enema for better control. (gastro.org)

• If mesalamine is not tolerated or does not work, use a rectal steroid such as budesonide foam or hydrocortisone enema. (pmc.ncbi.nlm.nih.gov)

• Severe symptoms, fever, or many bowel movements suggest more extensive disease. Those situations usually need systemic therapy rather than topical therapy alone. (gastro.org)

Choosing the right form

Evidence for reach and dosing is from imaging and prescribing information. (pubmed.ncbi.nlm.nih.gov)

How to use them well

• Try to empty the bowels first.

• Use at bedtime when possible to help retention.

• For enemas, lie on the left side with the right knee bent. Insert the tip gently toward the belly button. Squeeze steadily, then stay on the left side for at least 30 minutes, and try to keep it in all night.

• For suppositories, insert pointed end first and try to retain 1 to 3 hours or longer.

• Budesonide foam can be used standing, sitting, or lying. Warm and shake the canister before use. (my.clevelandclinic.org)

Dosing, duration, and maintenance

• Mesalamine suppository: 1 g at bedtime for 3 to 6 weeks. For maintenance in proctitis, 0.5 to 1 g daily or 1 g three times per week can help prevent relapse. (drugs.com)

• Mesalamine enema: 4 g nightly for 3 to 6 weeks. Some people use it intermittently after remission if symptoms recur. Combination oral plus rectal mesalamine is more effective than either alone for induction. (drugs.com)

• Budesonide foam: 2 mg per dose. Use twice daily for 2 weeks, then once daily for 4 weeks. Do not use long term for maintenance. (drugs.com)

• Hydrocortisone enema: 100 mg nightly as a retention enema. Try to keep in at least 1 hour, ideally overnight. Avoid long courses because of systemic steroid absorption. (drugs.com)

Safety and side effects

• Mesalamine: mostly local effects like rectal irritation, cramping, or urgency. Rare kidney problems can occur. Kidney function should be checked before starting and during treatment. Do not use with salicylate allergy. (drugs.com)

• Rectal steroids: can cause local burning or irritation. Budesonide has low systemic exposure, but hydrocortisone enemas may be absorbed and can cause steroid effects if used for long periods. (drugs.com)

• Staining: mesalamine enemas and suppositories can stain fabric and surfaces. Use protective pads and clean up promptly. (medlineplus.gov)

When to step up treatment

• If bleeding, urgency, and frequency have not improved after about 2 to 4 weeks of correct use, therapy often needs adjustment. Options include higher‑dose oral 5‑ASA with rectal mesalamine, or, if still not controlled, short‑term oral steroids or advanced therapies per treat‑to‑target plans. (gastro.org)

• For proctitis not responsive to mesalamine, guidelines note options like rectal steroids or, in select cases, tacrolimus suppositories. These are specialist‑directed. (journals.lww.com)

Practical tips

• If retention is hard, start with smaller volumes or use foam first, then switch to enemas as symptoms settle.

• Warm the enema bottle in the hands to reduce cramping.

• Use a barrier cream around the anus to protect skin if leakage occurs.

• Build a routine, for example every night after the last bathroom visit. (my.clevelandclinic.org)

FAQs

How do suppositories, foams, and enemas differ

Suppositories treat only the rectum. Foams spread higher than suppositories and are easier to retain. Enemas reach the sigmoid and often the splenic flexure, so they cover the largest area. (pubmed.ncbi.nlm.nih.gov)

Can rectal therapy be combined with oral medicine

Yes. Adding rectal mesalamine to oral 5‑ASA improves induction of remission in left‑sided or extensive disease compared with oral therapy alone. (gastro.org)

Are rectal steroids safe

They are useful for short courses. Budesonide foam has low systemic exposure. Hydrocortisone enemas can be absorbed, so prolonged use can cause steroid side effects. These are not recommended for maintenance. (drugs.com)

How quickly should symptoms improve

Many people notice less bleeding and urgency within 1 to 3 weeks. Keep using as prescribed and check back if symptoms are not improving after a few weeks. (drugs.com)

Who should avoid mesalamine

People with known allergy to aminosalicylates or salicylates should not use it. Kidney disease requires caution and monitoring. (drugs.com)