Possible food poisoning?
Symptoms occur within 6hr
Does it resolve (osmotic) or persist (secretory) with fasting?
Are the stools of smaller volume (large intestine) or larger volume (small intestine)
Fever or abdominal pain? (diverticulitis, gastroenteritis, IBD)
Bloody or melenic?
Tenesmus? (shigella)
Malodorous? (giardia)
Recent travel? (Traveler's<unk> 
Recent antibiotics? (C. diff)
HIV/immunocompromised/high risk behaviors?
Heat intolerance and anxiety? (thyrotoxicosis)
Paresthesias or reverse temperature sensation? (Ciguatera)
Symptoms occur within 6hr
Thyroid masses
Oral ulcers, erythema nodosum, episcleritis, anal fissure (IBD)
Reactive arthritis (Arthritis, conjunctivitis, urethritis)
Suggests infection with salmonella, shigella, campylobacter, or yersinia
Rectal exam for fecal impaction
Guaiac
Abdominal pain out of proportion to exam (mesenteric ischemia)
Suggests infection with salmonella, shigella, campylobacter, or yersinia
Acute diarrhea
Viral 
Acute gastroenteritis 
Bacterial
Acute gastroenteritis
Campylobacter
Acute fever
Shigella