Pain Characteristics and Location:

• Location and character of pain will often guide the diagnosis.
• Colicky pain is often seen in obstruction cases (gallstones, kidney stones, bowel obstruction) while a constant, dull ache might suggest inflammation.
• Pain that radiates to the back might suggest pancreatic pathology, whereas pain radiating to the right shoulder may indicate gallbladder disease.
• Pain that worsens on eating might suggest gastric ulcer or pancreatitis while pain that gets better with eating might suggest duodenal ulcer.

Medications and Their Effects:

• NSAIDs can cause gastritis or peptic ulcers
• Steroids can lead to peptic ulcers
• Opioids and iron supplements can cause constipation
• Antibiotics can lead to Clostridium difficile infection‍

Specific Populations and Symptoms:

• Elderly patients and immunocompromised patients may present with more subtle symptoms, even in severe conditions like appendicitis or perforated ulcers. Always maintain a high index of suspicion in these populations.
• Unexplained iron deficiency anemia in a postmenopausal woman or a man should prompt a search for a gastrointestinal cause, including malignancy.

‍The Abdominal Exam:

• Acute Abdomen - severe tenderness, rigidity (involuntary guarding), rebound tenderness.
• Voluntary guarding - when a patient tenses their abdominal muscles in response to the approach or touch of the examiner. It's a conscious, or at least semi-conscious, act often driven by the anticipation of pain. You may notice that muscle tension eases when the patient is distracted or reassured.
• Involuntary guarding or Rigidity - an unconscious reflex contraction of the abdominal wall muscles that occurs in response to inflammation of the parietal peritoneum. Unlike voluntary guarding, this muscle contraction does not ease with distraction or reassurance and may remain constant.
• Rebound tenderness - the abrupt “release” movement can cause the organs and the inflamed peritoneum to briefly shift and rub against each other. The underlying mechanism is thought to be due to irritation of the parietal peritoneum, which is sensitive to pain, stretch, and temperature (unlike the visceral peritoneum, which is only sensitive to stretch and pressure).
• Murphy's Sign - pain on palpation of the right upper quadrant during inspiration is suggestive of cholecystitis
• McBurney's Point Tenderness - Pain when pressure is applied and then quickly released in the right lower quadrant, approximately 2 inches from the anterior superior iliac spine on a straight line drawn to the umbilicus is suggestive of appendicitis
• Rovsing's Sign - pain in the right lower quadrant during palpation of the left lower quadrant is suggestive of appendicitis.
• Psoas Sign - pain when the patient's right thigh is passively extended or when the patient actively flexes at the hip is suggestive of retrocecal appendicitis
• Obturator Sign - pain when the hip and knee are flexed and the leg is rotated internally and externally is suggestive of pelvic appendicitis
• Kehr's Sign - left shoulder pain referred from a splenic injury
• Cullen Sign - periumbilical bruising that can be suggestive of hemoperitoneum or acute pancreatitis with hemmorrhage
• Grey Turner Sign - bruising on the flanks that can be suggestive of retroperitoneal bleed or acute pancreatitis

• Evaluation of Acute Abdominal Pain in Adults - AAFP

• CPS - Abdominal Pain Thought Train
• Strong Medicine - An Approach to Acute Abdominal Pain