Gastroesophageal Reflux Disease (GERD): This condition is often exacerbated by lying down and can cause abdominal pain or discomfort that worsens after waking up due to increased acid production during sleep.

Peptic Ulcer Disease: Similar to GERD, peptic ulcers can cause pain that is worse in the morning due to increased gastric acid secretion during the night.
Functional Dyspepsia: This condition involves recurring signs and symptoms of indigestion that have no obvious cause, and symptoms can be worse in the morning.
Irritable Bowel Syndrome (IBS): Although IBS can cause pain at any time, some patients may experience worsening symptoms in the morning, possibly due to changes in bowel habits or motility during sleep.

Myocardial Infarction: Although less common, myocardial infarction can present with epigastric pain, especially in women, and can occur at any time, including upon waking.
Pulmonary Embolism: Severe, sudden-onset chest pain can radiate to the abdomen and may be mistaken for abdominal pain; it's crucial to consider this diagnosis, especially if the pain is severe and accompanied by respiratory symptoms.
Aortic Dissection: This is a medical emergency that can present with severe, tearing abdominal or back pain and can occur at any time, including upon waking.

Intestinal Obstruction: Although typically associated with more acute symptoms, partial obstructions can cause intermittent pain that might be worse in the morning due to increased intestinal motility after waking.
Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease or ulcerative colitis can cause chronic abdominal pain, which might be perceived as worse in the morning due to bowel habits or increased inflammation during sleep.
Abdominal Migraine: A rare condition that can cause recurrent episodes of severe abdominal pain, often accompanied by other migraine symptoms, and can occur at any time, including upon waking.