Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease or ulcerative colitis can cause enteritis and may be associated with extraintestinal manifestations, including limb pain due to arthritis or other musculoskeletal issues.

Irritable Bowel Syndrome (IBS): While primarily causing gastrointestinal symptoms, IBS can sometimes be associated with extraintestinal symptoms, including musculoskeletal pain.
Infectious Gastroenteritis: Certain infections can cause both gastrointestinal and systemic symptoms, including limb pain, especially if the infection leads to a systemic inflammatory response.
Food Intolerance or Allergy: Conditions like celiac disease or lactose intolerance can cause gastrointestinal symptoms and may also lead to systemic symptoms, including joint pain, due to inflammation or malabsorption.

Systemic Lupus Erythematosus (SLE): An autoimmune disease that can cause a wide range of symptoms, including gastrointestinal issues and joint pain. Missing this diagnosis could lead to significant morbidity.
Rheumatoid Arthritis: While primarily an autoimmune disease affecting the joints, rheumatoid arthritis can also cause gastrointestinal symptoms and must be considered to avoid missing a potentially treatable condition.
Vasculitis: Conditions like Henoch-Schönlein purpura can cause both gastrointestinal symptoms (enteritis) and limb pain due to vasculitic changes.

Ehlers-Danlos Syndrome: A group of disorders that affect connective tissues supporting the skin, bones, blood vessels, and many other organs and tissues. Gastrointestinal symptoms and joint hypermobility can occur.
Whipple's Disease: A rare, systemic bacterial infection that can cause malabsorption, weight loss, joint pain, and other systemic symptoms.
Sarcoidosis: An inflammatory disease that can affect multiple organs in the body, including the gastrointestinal tract and joints, though gastrointestinal involvement is less common.