Orris

24 year old male patient with severe stomach pain. No history of eating outside and fever.

Reading File
Asking for Preferences
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Reading File
Reading File
Finding Sources
Finding Sources
Reading File
Reading File
I now have solid textbook content. Let me compile a comprehensive clinical response.

Clinical Assessment: 24-Year-Old Male with LLQ Colicky Pain + Change in Bowel Habit

Differential Diagnosis (Most to Least Likely)

RankDiagnosisKey Reasoning
1Irritable Bowel Syndrome (IBS)Young adult, colicky LLQ pain, altered bowel habit, no fever, no food exposure
2Crohn Disease (IBD)Typical age: 2nd–3rd decade; colicky lower abdominal pain, change in bowel habit
3Sigmoid/Descending Colon PathologyLLQ colicky pain localizes to sigmoid colon
4Intestinal Worm Infestation (Helminths)Colicky periumbilical/LLQ pain, bowel changes in young males even without recent outside food
5Functional Abdominal PainExclusion diagnosis in young patients

1. Irritable Bowel Syndrome (IBS) — Top Consideration

Rome IV Diagnostic Criteria (from ROSEN's Emergency Medicine):
  • Recurrent abdominal pain >1 day/week in the past 3 months, with onset >6 months prior
  • Pain associated with ≥2 of the following:
    • Pain related to defecation
    • Change in frequency of stool
    • Change in form/appearance of stool
  • No "red flag" warning signs (age >50, GI bleeding, weight loss, family history of colorectal cancer)
This patient fits: young age, colicky pain, change in bowel habit, no fever.
IBS Subtypes:
  • IBS-D — diarrhea-predominant
  • IBS-C — constipation-predominant
  • IBS-M — mixed
  • Post-infectious IBS occurs in 10–30% after gastroenteritis
Pathophysiology: Altered gut microbiome, intestinal permeability changes, brain-gut axis dysfunction, visceral hypersensitivity.

2. Crohn Disease — Must Rule Out

From Sabiston Textbook of Surgery:
"Crohn disease can occur at any age, but the typical patient is a young adult in the second or third decade of life. The most common symptom is chronic diarrhea, followed by intermittent and colicky abdominal pain, most commonly noted in the lower abdomen."
Key distinguishing features from IBS:
  • Low-grade fever in ~1/3 of patients (absent here — lowers suspicion, but doesn't exclude)
  • Weight loss, malaise
  • Perianal disease (fistulas, skin tags)
  • Elevated inflammatory markers (CRP, ESR, fecal calprotectin)
  • Symptomatic periods alternate with asymptomatic intervals
From ROSEN's Emergency Medicine:
"Crohn disease's transmural inflammation can affect any area of the GI tract... Common complications include fistulae, strictures, or abscesses."

Recommended Workup

Bedside / Basic Labs:
  • Full blood count (CBC) — look for anemia, leukocytosis
  • CRP, ESR — elevated in IBD, normal in IBS
  • Stool routine examination + culture — rule out parasites, infection
  • Stool occult blood test
If IBD suspected:
  • Fecal calprotectin — highly sensitive for intestinal inflammation; helps distinguish IBD from IBS
  • LFTs, albumin (nutritional status in Crohn)
Imaging:
  • Ultrasound abdomen — first-line; look for bowel wall thickening, free fluid
  • CT abdomen/pelvis — if complicated Crohn suspected (abscess, obstruction, perforation)
  • Colonoscopy with biopsy — gold standard for IBD diagnosis

Red Flags Requiring Urgent Attention

(None present currently, but watch for:)
  • Fever → suggests infectious cause or IBD complication
  • Bloody stool / mucus in stool → IBD or infectious colitis
  • Guarding/rigidity → perforation
  • Rebound tenderness → peritonitis
  • Unintentional weight loss → malignancy or IBD

Initial Management

If IBS most likely (no red flags):
  • Reassurance and lifestyle counseling
  • Dietary modification: low-FODMAP diet
  • Antispasmodics (e.g., mebeverine, hyoscine butylbromide) for colicky pain
  • Address any psychological stressors
  • Probiotics may help some patients
If IBD suspected (elevated calprotectin / abnormal imaging):
  • Refer to gastroenterology for colonoscopy
  • Aminosalicylates (5-ASA) for colonic Crohn / UC
  • Avoid NSAIDs (can worsen IBD)
Bottom Line: In a 24-year-old male with LLQ colicky pain and change in bowel habit but no fever, IBS is the leading diagnosis, but Crohn disease must be excluded with fecal calprotectin and colonoscopy before labeling as functional. The absence of fever and food exposure makes acute infectious causes less likely.
Sources: ROSEN's Emergency Medicine, 10e; Sabiston Textbook of Surgery, 21e; Sleisenger & Fordtran's GI and Liver Disease
This is a shared conversation. Sign in to Orris to start your own chat.