Inflammatory bowel disease (IBD)

Chronic autoimmune intestinal diseases — Crohn disease and ulcerative colitis. Therapy depends on severity and location — mesalazine, corticosteroids, thiopurines (azathioprine), and biologics.

ICD-10 K50/K513 drugs

Also known as: Crohn, Ulcerative colitis

Drugs used for this condition

BAzathioprineSecond line · Immunosuppressants, thiopurinesPer AGA 2021, for moderate-to-severe Crohn disease and ulcerative colitis, biologics and small molecules are now preferred first-line; azathioprine has moved to second-line, used as a combination partner with an anti-TNF agent (to reduce immunogenicity, SONIC trial) or as maintenance in milder or step-up settings. Dose 2–2.5 mg/kg/day, effect over 8–16 weeks. Reduces flare frequency, corticosteroid requirements, and hospitalizations. Azathioprine monotherapy is not first-line for active moderate-to-severe disease. TPMT activity (and where possible NUDT15) must be tested before start, with blood-count monitoring for myelosuppression. The thiopurine plus anti-TNF combination carries the highest risk of hepatosplenic T-cell lymphoma, mainly in young men, and raises the risk of lymphoma and non-melanoma skin cancer.
BMethotrexateSecond line · Antimetabolites, folic acid analoguesIn Crohn disease, methotrexate is used as a thiopurine alternative when those agents are intolerated or ineffective per AGA 2021 and ECCO 2020. Evidence is weaker in ulcerative colitis, where methotrexate is rarely used. Dose 25 mg subcutaneously weekly.

Marketing claims without evidence base

The drug is promoted for these uses outside international guidelines. Each entry below is analyzed against AEMPS, FDA, EMA, Cochrane and major RCTs.

DSlippery elm (inner bark)Not recommended · Over-the-counter botanical supplement, the inner bark of Ulmus rubra (slippery elm, a North American tree); a mucilage demulcent with traditional use for irritation of the gastrointestinal and throat mucosaSlippery elm (Ulmus rubra) is a herbal remedy made from the tree's inner bark, promoted for inflammatory bowel disease (Crohn's disease, ulcerative colitis) as a gentle mucilaginous agent. No reliable evidence shows it helps in IBD – there's no evidence base for this use. What does work in IBD are treatments with proven benefit: aminosalicylates, corticosteroids for flares, immunosuppressants, and biologics prescribed by a gastroenterologist. The substance itself is harmless in this role, but don't use it instead of treatment with proven benefit – you could lose control of the disease.

How to read tiers A–F

Evidence tiers belong to the drug-indication pair, not to the drug as a whole: the same substance can be A for one condition and F for another.

AStrong evidence – first or second line in international guidelines
BRecommended in selected cases
CStudy data contradict each other
DBenefit not proven, no documented harm
FDocumented harm, or risk without benefit