Diclofenac can cause stomach ulcers in people taking large doses or taking it for a long time. Due to this, it is recommended to take Diclofenac with or straight after food or a glass of milk. Taking Diclofenac with food will lessen the likeliness of experiencing stomach irritation.
If you are prone to stomach ulcers, or have had one in the past, speak with your doctor about this risk before you take Diclofenac.