Etoricoxib 90 mg is a painkiller that may reduce discomfort, but it is not usually the first choice for pain from an anal fissure. Since you also have abdominal pain, it is important to be cautious, as this medicine can sometimes cause stomach-related side effects and may not be suitable for everyone. Safer options such as paracetamol, along with stool softeners and topical anaesthetics for the fissure, are generally preferred initially. It is best to consult a doctor before starting Etoricoxib to ensure it is appropriate for your condition.