The cornerstone of treatment for mild ulcerative colitis is still the oral or topical (rectal) application of aminosalicylates (5-ASA). 5‑ASA preparations are often only administered orally in mild ulcerative colitis. Study data show that in ulcerative proctitis and left-sided colitis, rectal 5‑ASA preparations are even more effective than oral administration. In a next step, steroid-containing topical therapies should be used. Topical steroids such as budesonide are also primarily used in mild Crohn's disease. However, it is controversial whether treatment is necessary in symptom-free patients. There is still a lack of evidence to prove that more aggressive treatment (using immunosuppressants, biologics or small molecules) has a long-term benefit in these patients. Most guidelines are critical of the use of 5‑ASA in mild Crohn's disease. Nevertheless, there is some evidence for sufficiently high-dose treatment with 5‑ASA, although one must be aware of its limited effectiveness. However, there is clear evidence for the postoperative use of 5‑ASA in cases of mild recurrence.