A 21-year-old male presents with a complaint of right upper quadrant (RUQ) pain for 48 hours, accompanied by nausea and anorexia. The pain began 8 hours after a drinking binge (approximately one-half liter of vodka) 2 days ago and has worsened over the past 2 days, increasing from a 2 to a 5 on the pain scale. The patient experienced vomiting twice the morning after the binge, but there has been no vomiting since. The emesis was clear/yellow with no blood, and the patient denies diarrhea. He reports having had similar pain only once before, months ago after drinking excessively, but it was less severe and resolved quickly without treatment. The patient is worried about the prolonged duration of the pain, which is affecting his sleep. He admits to binge drinking approximately twice a week for the past 2 years and has an anxiety disorder with panic attacks. He manages the anxiety with marijuana or by enduring it, having had a short course of Ativan about a year ago.

**Past Medical History:**
- Denies surgeries or serious illnesses/hospitalizations
- No regular medications; previously on SSRI but discontinued a couple of years ago

**Family History:**
- Father, age 55, has Parkinson’s disease
- Mother, age 52, has hypertension
- No history of alcohol/drug abuse or mental illness in the patient or family

**Psychosocial History:**
- Considers health to be good; usually eats well and exercises five times per week, lifting weights
- Alcohol abuse as mentioned, recreational marijuana use
- Doing well academically as a senior majoring in International Business
- In a monogamous relationship for the past 2 years, no use of condoms

**Review of Systems:**
- General: Denies fever or weight loss but reports difficulty eating due to abdominal pain and nausea
- HEENT: Denies headache, visual changes, redness, or "yellow" color of the eyes. Reports blackouts related to alcohol abuse
- Cardiovascular: Experiences chest tightness with panic/anxiety attacks. Denies chest pain, hypertension, hypotension, or palpitations
- Respiratory: Experiences shortness of breath with panic/anxiety attacks. No shortness of breath or dyspnea on exertion while lifting weights. No history of asthma or allergies. Does not smoke or chew tobacco
- Gastrointestinal: See details above. Denies epigastric pain or pain in the RLQ or LLQ. No history of peptic ulcer disease or H. pylori. No rectal bleeding or melena
- Musculoskeletal: Denies joint pain or swelling. Has right back pain, believed to be related to RUQ pain
- Genitourinary: Denies frequency, dysuria, hematuria. No history of renal calculi. No penile discharge. No history of STDs
- Neurological: Blackouts with drinking. Denies headaches, head injuries, dizziness, or balance difficulties except with alcohol
- Endocrine: Denies polyuria, polydipsia, polyphagia. No heat or cold intolerance. No weight loss or gain
- Hematology: Denies anemia, bleeding, or easy bruising
- Psychiatric: Complains of panic/anxiety attacks (see above). Attacks started in high school without any specific trigger. Stressful situations exacerbate the attacks, but they sometimes occur without an obvious cause

**Physical Examination:**
- Vital Signs: T 97.6°F, BP 150/80 mmHg, HR 92 bpm, RR 18 breaths/min, O2 saturation 99%, height 72 inches, weight 180 lbs
- General: Well-developed, well-nourished male who is visibly anxious with sweat beads on forehead and nose
- HEENT: Sclera nonicteric. Pupils equal, round, and reactive to light and accommodation. No exophthalmos or lid lag. Tympanic membranes with good light reflex, no inflammation. Posterior pharynx not inflamed, no cervical lymphadenopathy. Thyroid not enlarged or nodular
- Cardiovascular: Regular rate and rhythm without murmurs, S3, S4, splits, or rubs. No lower extremity edema. No carotid bruits
- Respiratory: Even and unlabored rate. No adventitious sounds
- Abdomen: Bowel sounds present in all four quadrants. No aortic or renal bruits. Tenderness on palpation in RUQ. Liver percusses 6 cm in midclavicular line. No rebound tenderness. Right costovertebral angle tenderness on percussion. No RLQ tenderness, negative psoas sign, negative obturator sign, negative McBurney’s sign. No epigastric tenderness. Stool guaiac negative
- Musculoskeletal: No joint swelling or tenderness. Full range of motion in all joints. No chest wall tenderness but states that RUQ pain increases with bending forward and lying down. Strength 5/5 in all four extremities
- Genitourinary: Negative for hernia, testicular masses, penile lesions, or discharge
- Neurological: Cranial nerves II to XII within normal limits. Deep tendon reflexes 2+ bilaterally. Sensory and motor functions without deficits. Negative Romberg test

**Differential Diagnosis:**
1. Acute pancreatitis: The pain started after binge drinking, and the location and nature of the pain are consistent with this diagnosis. The patient's history of alcohol use supports this possibility.
2. Cholecystitis: RUQ pain and nausea, along with the timing related to alcohol intake, suggest this as a potential diagnosis.
3. Hepatitis: Due to the alcohol use and RUQ tenderness, hepatitis (possibly alcohol-induced) could be considered.

**Further History, Examination, and Diagnostic Studies:**
- Obtain a detailed history of alcohol use and any dietary triggers
- Perform a thorough abdominal examination, focusing on liver and gallbladder regions
- Order laboratory tests: complete blood count, liver function tests, amylase, and lipase levels
- Conduct an abdominal ultrasound or CT scan to assess for gallstones, liver pathology, or pancreatic inflammation