These alternative diagnoses include but are not limited to:
Perforated peptic ulcer
Acute pancreatitis
Liver abscess
Pneumonia
Myocardial ischemia
Hiatal hernia
Biliary colic
Choledocholithiasis
Cholangitis
Appendicitis
Colitis
Acute peptic ulcer exacerbation
Amoebic liver abscess
Acute intestinal obstruction
Kidney stone
Biliary ascariasis

Treatment
Surgery
For most people with acute cholecystitis, the treatment of choice is surgical removal of the gallbladder, laparoscopic cholecystectomy. Laparoscopic cholecystectomy is performed using several small incisions located at various points across the abdomen. Several studies have demonstrated the superiority of laparoscopic cholecystectomy when compared to open cholecystectomy (using a large incision in the right upper abdomen under the rib cage). People undergoing laparoscopic surgery report less incisional pain postoperatively as well as having fewer long-term complications and less disability following the surgery. Additionally, laparoscopic surgery is associated with a lower rate of surgical site infection.During the days prior to laparoscopic surgery, studies showed that outcomes were better following early removal of the gallbladder, preferably within the first week. Early laparoscopic cholecystectomy (within 7 days of visiting a doctor with symptoms) as compared to delayed treatment (more than 6 weeks) may result in shorter hospital stays and a decreased risk of requiring an emergency procedure. There is no difference in terms of negative outcomes including bile duct injury or conversion to open cholecystectomy. For early cholecystectomy, the most common reason for conversion to open surgery is inflammation that hides Calots triangle. For delayed surgery, the most common reason was fibrotic adhesions. Other
Supportive measures may be instituted prior to surgery. These measures include fluid resuscitation. Intravenous opioids can be used for pain control.Antibiotics are often not needed.
Yellowing of the skin (jaundice) may occur but is often mild. Severe jaundice suggests another cause of symptoms such as choledocholithiasis. People who are old, have diabetes, chronic illness, or who are immunocompromised may have vague symptoms that may not include fever or localized tenderness. Complications
A number of complications may occur from cholecystitis if not detected early or properly treated. Signs of complications include high fever, shock and jaundice. Complications include the following:
Gangrene
Gallbladder rupture
Empyema
Fistula formation and gallstone ileus
Rokitansky-Aschoff sinuses

Gangrene and gallbladder rupture
Cholecystitis causes the gallbladder to become distended and firm. Distension can lead to decreased blood flow to the gallbladder, causing tissue death and eventually gangrene. Once tissue has died, the gallbladder is at greatly increased risk of rupture (perforation), which can cause sharp pain. Rupture can also occur in cases of chronic cholecystitis. Rupture is a rare but serious complication that leads to abscess formation or peritonitis. Massive rupture of the gallbladder has a mortality rate of 30%. Empyema
Untreated cholecystitis can lead to worsened inflammation and infected bile that can lead to a collection of pus inside the gallbladder, also known as empyema. The symptoms of empyema are similar to uncomplicated cholecystitis but greater severity: high fever, severe abdominal pain, more severely elevated white blood count. Fistula formation and gallstone ileus
The inflammation of cholecystitis can lead to adhesions between the gallbladder and other parts of the gastrointestinal tract, most commonly the duodenum. These adhesions can lead to the formation of direct connections between the gallbladder and gastrointestinal tract, called fistulas.