Constipation: This is a common issue in the elderly due to decreased mobility, medication side effects, and changes in bowel habits. It can cause significant abdominal pain and discomfort.
Diverticulitis: Inflammation of the diverticula in the colon, which is more common in older adults. Symptoms include abdominal pain, usually on the left side, fever, and changes in bowel habits.

Gastroesophageal Reflux Disease (GERD): Stomach acid flowing back into the esophagus can cause abdominal pain, especially after eating. This condition is common in all ages, including the elderly.
Peptic Ulcer Disease: Ulcers in the stomach or duodenum can cause abdominal pain, especially in the upper abdomen, and are more common in older adults due to the use of NSAIDs.
Cholecystitis: Inflammation of the gallbladder, often due to gallstones, can cause right upper quadrant abdominal pain, fever, and nausea.
Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause chronic abdominal pain, diarrhea, and weight loss, though they are less common in the elderly.

Mesenteric Ischemia: A reduction in blood flow to the intestines can cause severe abdominal pain out of proportion to physical examination findings. It is critical to diagnose early as it can lead to bowel infarction and death.
Abdominal Aortic Aneurysm (AAA): A rupture of the aorta can cause sudden, severe abdominal and back pain. It is a medical emergency requiring immediate intervention.
Pneumonia: In elderly patients, pneumonia can present with abdominal pain if the infection involves the lower lobes of the lungs, causing referred pain.
Myocardial Infarction: Though typically presenting with chest pain, myocardial infarction can sometimes cause epigastric discomfort or abdominal pain, especially in women and diabetic patients.

Pancreatic Cancer: Though more common in older adults, it is less likely than other causes of abdominal pain. It can cause weight loss, jaundice, and abdominal pain.
Intestinal Obstruction: A blockage in the intestine can cause severe abdominal pain, vomiting, and constipation. It is less common but requires prompt diagnosis and treatment.
Eosinophilic Gastroenteritis: A rare condition characterized by eosinophilic infiltration of the gastrointestinal tract, causing abdominal pain, nausea, and vomiting.
Amyloidosis: A condition where abnormal proteins (amyloid) accumulate in organs, including the gastrointestinal tract, causing a variety of symptoms including abdominal pain.