Case Study: A 31-Year-Old Male with Unexplained Weight Loss and Gastrointestinal Distress Post-Infection

Case at a Glance

A 31-year-old male presents with a six-week history of significant unintentional weight loss, anorexia, and multifactorial gastrointestinal symptoms. The onset was preceded by a flu-like illness for which he consumed a significant amount of ibuprofen. Initial workup, including blood tests, stool analysis, and abdominal ultrasound, was unremarkable, and empirical treatment with a proton-pump inhibitor and probiotics provided no relief.

Patient's Story

The patient is a 31-year-old male, with a height of 183 cm, who was in his usual state of health until approximately six weeks prior to presentation. At that time, he contracted a flu-like infection and self-medicated with a high intake of ibuprofen. Shortly after the illness resolved, he began to experience a profound loss of appetite. This led to an unintentional weight loss of 6 kg over six weeks (from 85 kg to 79 kg). He reports that his stool has become consistently soft, often light brown and sticky, with occasional mucus. He describes a persistent pressure sensation in his left flank that is typically relieved following a bowel movement. Additionally, he experiences intermittent bloating and a sensation of being full, even after consuming small amounts of food. A peculiar symptom he notes is a 'band-like' numbness around his abdomen that occurs primarily after eating. Other symptoms include a feeling of air rising from his esophagus after swallowing, occasional transient episodes of dizziness, and difficulty initiating sleep.

Initial Assessment

Upon presentation, the patient appeared well but anxious. Vital signs were stable. His BMI was 23.6 kg/m², down from a baseline of 25.4 kg/m². Physical examination revealed a soft, non-tender abdomen with normal bowel sounds. No organomegaly was palpated. The patient reported a subjective sensation of pressure upon deep palpation of the left flank, but there was no guarding or rebound tenderness. The initial diagnostic workup included complete blood count, comprehensive metabolic panel, and liver function tests, all of which were within normal limits. An abdominal ultrasound was performed and showed no abnormalities of the liver, gallbladder, spleen, pancreas, or kidneys.

The Diagnostic Journey

Given the dyspeptic symptoms, an empirical trial of Pantoprazole (a proton-pump inhibitor) was initiated, along with probiotics, for three weeks. The patient reported no improvement in any of his symptoms. A stool analysis was conducted to rule out common pathogenic bacteria, ova, and parasites, with results returning negative. The combination of persistent symptoms, significant weight loss, and failure of initial therapy prompted concern for a more complex underlying etiology. The preceding high use of NSAIDs raised suspicion for NSAID-induced enteropathy or gastropathy, while the post-infectious onset pointed towards possible post-infectious irritable bowel syndrome (IBS) or small intestinal bacterial overgrowth (SIBO).

Final Diagnosis

The final diagnosis remains pending. The primary differential diagnoses include:

1. NSAID-Induced Enteropathy/Gastropathy: Given the significant ibuprofen use prior to symptom onset, damage to the gastric or small intestinal mucosa is a leading consideration.
2. Post-Infectious Irritable Bowel Syndrome (PI-IBS): The timing of symptom onset following a viral illness is classic for this condition.
3. Functional Dyspepsia: Characterized by early satiety, bloating, and epigastric discomfort.
4. Small Intestinal Bacterial Overgrowth (SIBO): Can explain the bloating, altered bowel habits, and malabsorption. Inflammatory Bowel Disease (IBD) and Celiac disease are considered less likely given the normal initial bloodwork but have not been ruled out.

Treatment Plan

The initial treatment with Pantoprazole and probiotics was discontinued due to ineffectiveness. The current plan is focused on achieving a definitive diagnosis. The patient has been referred to a gastroenterologist for further evaluation. The recommended next steps include:

1. Upper Endoscopy (EGD): To visually inspect the esophagus, stomach, and duodenum for inflammation, ulceration, or other signs of NSAID damage. Biopsies will be taken to test for H. pylori and rule out microscopic changes.
2. Colonoscopy: To evaluate the colon for sources of altered bowel habits and rule out IBD.
3. Further Laboratory Testing: Including a Celiac disease panel (tTG-IgA) and inflammatory markers (CRP, ESR) to be thorough.

Outcome and Follow-up

The patient is awaiting his consultation with the gastroenterology service and subsequent endoscopic procedures. His management will be guided by the findings of these investigations. In the interim, he has been advised to avoid all NSAIDs, maintain a symptom diary, and focus on small, frequent meals to manage the early satiety and bloating. Follow-up is scheduled to review the results of the upcoming diagnostic tests and establish a targeted treatment plan.