Hi, Insulin Levemir is highly unlikely to be the cause of diarrhoea. It would have been helpful if you had mentioned about the duration and control of your diabetes. Some cases with long standing diabetes may present with diabetic diarhhea. Nevertheless, I would suggest you to consult your endocrinologist/ physician. Medications like antidiarrheal drugs and/ or certain antibiotics can be used to control this condition. Also there is no mention of concomitant drug intake. Some oral antidiabetics can cause gastric irritation leading to diarrhoea. If that is the case, then withholding the drug may be helpful. Thanks for writing into healthcaremagic. Have a wonderful day.