In people with ulcerative colitis or Crohn’s disease, fasting during Ramadan for one month does not lead to measurable changes in two biomarkers of inflammation: C-reactive protein in the blood and calprotectin in the stool.

In people with Crohn’s disease, fasting during Ramadan does not lead to measurable changes in blood markers of inflammation or symptom severity over one month.

People with ulcerative colitis who fast during Ramadan may experience worse symptoms, but this is not due to increased inflammation in the body, since standard inflammation markers do not change. Other factors like changes in when medications are taken, sleep patterns, or diet may be responsible.

In patients with ulcerative colitis, fasting during Ramadan for 14 to 15 hours per day is linked to a small but measurable increase in disease activity symptoms, especially in individuals aged 30 or older or those with higher baseline levels of fecal calprotectin, without corresponding changes in blood or stool markers of inflammation.

People with ulcerative colitis who have elevated levels of fecal calprotectin before Ramadan fasting are more likely to experience a worsening of their symptoms during the fasting period.

During Ramadan fasting, people with ulcerative colitis may experience worsening symptoms, while those with Crohn’s disease typically do not show a change in symptoms, suggesting that fasting affects these two conditions differently.