150 mg sodium butyrate twice a day for 12 weeks

placebo capsules twice a day for 12 weeks

add-on therapy irrespective of standard treatment depending on severity (according to the guidelines)

The Pediatric Crohn's Disease Activity Index (PCDAI) measured in points of activity was used to assess CD activity.

Severity of the disease:

<10 points = remission 10-27.5 points = mild Crohn's Disease 30-37.5 points = moderate Crohn's Disease

≥40 points = severe Crohn's Disease

In this scale addominal pain (mild or moderate/severe), number of stools per day, general well being (good, below par, very poor), antropometric measures, palpable mass in the abdomen and perianal fistulas are assessed. The scale is validated and used in daily clinical practice.

Remission was defined as less than 10 points for both PCDAI and PUCAI scores.

The Pediatric Ulcerative Colitis Activity Index (PUCAI) measured in points of activity was used to assess UC activity.

Severity of the disease:

<10 points = remission 10-34 points = mild ulcerative colitis 35-64 points = moderate ulcerative colitis

≥65 points = severe ulcerative colitis

In this scale addominal pain (mild or moderate/severe), number of stools per day, blood in the stool, stool consistency, nocturnal stools and activity level (no limitation, occasional or restricted), are assessed. The scale is validated and used in daily clinical practice.

Remission was defined as less than 10 points for both PCDAI and PUCAI scores.

assessed separately, calcultated in points (described above)

measured in µg/g assessed in different soubgroups (lower result is better, remission = less than 50.