In Britain the Medicines and Healthcare products Regulatory Agency (MHRA) said in June 2013 that the drug should not be used by people with serious underlying heart conditions – people who had had heart failure, heart disease or a stroke were advised to stop using it completely. As of 15 January 2015, the MHRA announced that diclofenac will be reclassified as a prescription-only medicine (POM) due to the risk of cardiovascular adverse events.A subsequent large study of 74,838 Danish users of NSAIDs or coxibs found no additional cardiovascular risk from diclofenac use. A very large study of 1,028,437 Danish users of various NSAIDs or coxibs found the "Use of the nonselective NSAID diclofenac and the selective cyclooxygenase-2 inhibitor rofecoxib was associated with an increased risk of cardiovascular death (odds ratio, 1.91; 95% confidence interval, 1.62 to 2.42; and odds ratio, 1.66; 95% confidence interval, 1.06 to 2.59, respectively), with a dose-dependent increase in risk. "Diclofenac is similar in COX-2 selectivity to celecoxib. Gastrointestinal
Gastrointestinal complaints are most often noted. The development of ulceration and/or bleeding requires immediate termination of treatment with diclofenac. Most patients receive a gastro-protective drug as prophylaxis during long-term treatment (misoprostol, ranitidine 150 mg at bedtime or omeprazole 20 mg at bedtime). Liver
Liver damage occurs infrequently, and is usually reversible. Hepatitis may occur rarely without any warning symptoms and may be fatal. Patients with osteoarthritis more often develop symptomatic liver disease than patients with rheumatoid arthritis. Liver function should be monitored regularly during long-term treatment.
Hemoperitoneum  (also haemoperitoneum, sometimes also hematoperitoneum) is the presence of blood in the peritoneal cavity. The blood accumulates in the space between the inner lining of the abdominal wall and the internal abdominal organs. Hemoperitoneum is generally classified as a surgical emergency; in most cases, urgent laparotomy is needed to identify and control the source of the bleeding. In selected cases, careful observation may be permissible. The abdominal cavity is highly distensible and may easily hold greater than five liters of blood, or more than the entire circulating blood volume for an average-sized individual. Therefore, large-scale or rapid blood loss into the abdomen will reliably induce hemorrhagic shock and, if untreated, may rapidly lead to death. Causes
Causes of hemoperitoneum include:
Penetrating trauma
Blunt trauma, most commonly injuries to solid organs such as the liver and spleen. Vascular accidents, such as rupture of an abdominal aortic aneurysm, iliac aneurysm, or splenic aneurysm. Bleeding due to a ruptured ectopic pregnancy or uterine rupture. Rupture of corpus luteum in some cases. Less commonly, bleeding due to a perforated gastric ulcer. Bleeding due to rupture of an intra-abdominal neoplasm, (e.g., Hepatoblastoma)
Disseminated intravascular coagulation
People on high dose of anticoagulants (blood thinners)
Perforation of the colon

Diagnosis
Hemoperitoneum can be reliably diagnosed with the following examinations:
Focused assessment with sonography for trauma (FAST)
Paracentesis or diagnostic peritoneal lavage
Computed tomography
Diagnostic laparoscopy or exploratory laparotomy

Treatment
Initial management consists of immediate blood transfusion if the patient is in hemorrhagic shock.