Gallstone ileus is a rare but life-threatening mechanical bowel obstruction caused by impaction of a gallstone that has migrated through a cholecystoenteric fistula into the gastrointestinal tract. It accounts for 1–4% of all mechanical bowel obstructions and up to 25% of nonstrangulated small bowel obstructions in patients over 65. [1-3] In-hospital mortality ranges from 6.7–18%, largely driven by the elderly, comorbid patient population. [2-3]
The following figure demonstrates the classic radiographic and intraoperative findings of gallstone ileus, including the intraluminal filling defect and surgical stone extraction from the terminal ileum:
1. History
- Key HPI questions: Onset, duration, and character of abdominal pain; nausea/vomiting (bilious vs. feculent); last bowel movement/flatus; obstipation vs. constipation; prior episodes of biliary colic or cholecystitis
- Symptom characterization: Crampy, intermittent abdominal pain often with a "tumbling" pattern — symptoms may wax and wane as the stone transiently impacts and dislodges ("tumbling obstruction") [5-6]
- Timing: Median symptom duration before diagnosis is 3 days (range 1–28 days); delayed presentation is common [5]
- Associated symptoms: Abdominal distension, vomiting (may become feculent), anorexia, weight loss
- Important negatives: Ask about prior cholecystectomy (post-cholecystectomy gallstone ileus from lost stones is a recognized entity, with latency up to 50 years); prior abdominal surgery (adhesive SBO is the main competing diagnosis) [7]
2. Alarm Features
- Feculent vomiting, complete obstipation, or rapidly worsening distension → complete obstruction
- Peritoneal signs (rigidity, rebound) → bowel ischemia, perforation, or necrosis
- Hemodynamic instability (tachycardia, hypotension) → sepsis or third-spacing
- High-grade fever → perforation, abscess, or cholangitis
- Bouveret syndrome (gastric outlet obstruction from stone impacted in duodenum) — persistent non-bilious vomiting with inability to tolerate any PO [8]
3. Medications
- Relevant contributors: Opioids and anticholinergics may mask or worsen ileus symptoms
- Acute treatment: IV fluid resuscitation, electrolyte correction, antiemetics (ondansetron), NGT decompression; broad-spectrum antibiotics if signs of sepsis or perforation (e.g., piperacillin-tazobactam)
- Contraindicated: Prokinetics are not useful in mechanical obstruction; avoid oral contrast if high-grade obstruction is suspected
- Post-op: Ursodeoxycholic acid has no established role in preventing recurrence
4. Diet
- Acute: NPO with NGT decompression for bowel rest and gastric decompression
- Hydration: Aggressive IV crystalloid resuscitation — these patients are often severely dehydrated and volume-depleted from vomiting and third-spacing
- Post-operative: Advance diet slowly (clear liquids → regular) once bowel function returns
- Long-term: Standard cholelithiasis dietary counseling (low-fat diet) if gallbladder remains in situ
5. Review of Systems
- GI: Nausea, vomiting, abdominal pain pattern, distension, flatus, bowel habits, hematemesis/melena
- Hepatobiliary: Prior RUQ pain, jaundice, dark urine, clay-colored stools (cholangitis risk with persistent fistula) [9]
- Constitutional: Fever, weight loss, fatigue
- Cardiovascular/Pulmonary: Baseline cardiopulmonary reserve (critical for surgical planning — 86% of patients are ASA class 3–4) [5]
- Renal: Urine output — acute renal failure is the most common postoperative complication (30%) [2]
6. Collateral History and Family History
- Collateral: Prior imaging showing gallstones, history of cholecystitis or biliary interventions, prior abdominal surgeries, baseline functional status and cognitive function (important for surgical risk stratification in elderly)
- Family history: Cholelithiasis has familial predisposition; otherwise family history is of limited utility in acute management
- Social context: Living situation and support system (relevant for post-discharge planning in elderly patients)
7. Risk Factors
- Age >65 — median age at presentation is 74–78 years [2][5][10]
- Female sex — female-to-male ratio approximately 3.5–4.5:1 [2][5]
- Chronic cholelithiasis with recurrent cholecystitis (creates the inflammatory milieu for fistula formation) [6]
- Large gallstones (>2–2.5 cm) — stones must be large enough to obstruct the bowel lumen; mean impacted stone size is 3.6 cm [5]
- Multiple comorbidities — cardiovascular disease, diabetes, renal insufficiency [2]
- Prior cholecystectomy with spilled/lost stones (rare mechanism) [7]
8. Differential Diagnosis
- Adhesive small bowel obstruction — most common SBO cause; no pneumobilia; history of prior surgery
- Incarcerated/strangulated hernia — examine all hernia orifices
- Small bowel tumor or stricture — insidious onset, weight loss
- Bezoar — history of gastroparesis, psychiatric illness
- Bouveret syndrome — gallstone impacted in duodenum causing gastric outlet obstruction (variant of gallstone ileus) [8]
- Mesenteric ischemia — pain out of proportion to exam, atrial fibrillation
- Intussusception — colicky pain, "currant jelly" stool
- Crohn's stricture — young patient, chronic diarrhea, known IBD
- Primary enterolith — tends to be proximal, low-density, gas-containing on CT (vs. calcified gallstones distally) [11]
9. Past Medical History
- Prior biliary disease: History of gallstones, cholecystitis, biliary colic, ERCP, or cholecystectomy
- Previous episodes: Recurrent SBO episodes or "tumbling" pattern of intermittent obstruction
- Surgical history: Prior abdominal surgery (adhesions as competing diagnosis); prior cholecystectomy (lost stone mechanism)
- Comorbidities: Cardiovascular disease, diabetes, CKD, COPD — directly impact surgical risk and mortality [2][5]
10. Physical Exam
- Vital signs: Tachycardia, hypotension (dehydration/sepsis), fever (perforation/cholangitis)
- Abdominal exam:
- Distension (often prominent)
- High-pitched or absent bowel sounds
- Diffuse tenderness, often periumbilical
- RUQ tenderness or mass (inflamed gallbladder/fistula)
- Peritoneal signs (rebound, guarding) → surgical emergency
- Hernia orifices: Must examine inguinal, femoral, umbilical, and incisional sites to exclude incarcerated hernia
- Rectal exam: Empty rectal vault (complete obstruction); rarely a gallstone may be palpable in the rectum
- Volume status: Dry mucous membranes, poor skin turgor, delayed capillary refill
11. Lab Studies
- CBC: Leukocytosis (infection, ischemia); anemia (chronic disease)
- BMP/CMP: Electrolyte derangements (hypokalemia, hyponatremia, metabolic alkalosis from vomiting); BUN/Cr elevated (dehydration, AKI — most common postoperative complication at 30%) [2]
- Hepatic panel: LFTs, bilirubin, alkaline phosphatase — may be elevated if concurrent cholangitis or CBD obstruction
- Lipase: Rule out concurrent gallstone pancreatitis
- Lactate: Elevated if bowel ischemia or sepsis
- Coagulation studies: Pre-operative baseline
- Type and screen: Pre-operative preparation
- Blood gas: Assess acid-base status in critically ill patients
12. Imaging
- Plain abdominal radiograph (first-line in ED):
- Air-fluid levels and dilated bowel loops (seen in ~78–89%) [12]
- Pneumobilia (37% on plain film) [12]
- Ectopic calcified gallstone (33% on plain film) [12]
- The complete Rigler triad (pneumobilia + SBO + ectopic stone) is seen on plain film in only ~15% of cases [12]
- CT abdomen/pelvis with IV contrast (gold standard):
- Sensitivity 93%, specificity 100%, accuracy 99% for gallstone ileus [13]
- Rigler triad identified on CT in ~78% of cases [12]
- Identifies stone location, size, number, and presence of bilioenteric fistula
- Detects bowel wall thickening, ischemia, or perforation
- CT diagnostic criteria: (1) SBO, (2) ectopic gallstone (rim- or fully calcified), (3) abnormal gallbladder with air or fluid [13]
- Ultrasound: Useful adjunct — may show contracted/abnormal gallbladder, pneumobilia (56%), but limited for ectopic stone detection (15%) [12]
- MRI/MRCP: Can visualize the fistula tract (100% sensitivity for fistula) but rarely needed acutely [14]
- When imaging is unnecessary: CT is almost always indicated when gallstone ileus is suspected; do not delay for additional imaging if clinical picture is clear
13. Special Tests
- Rigler triad (diagnostic triad): Pneumobilia + bowel obstruction + ectopic gallstone — pathognomonic when all three are present [1][15]
- Rigler tetrad (fourth sign): Change in position of a previously seen gallstone on serial imaging [1]
- ERCP: May be considered for Bouveret syndrome (duodenal impaction) for attempted endoscopic lithotripsy, though success rates are limited [6]
- Intraoperative: Systematic palpation of the entire bowel is mandatory — 16% of cases have more than one ectopic stone [10][15]
14. ECG
- Indications: Pre-operative ECG in all patients (elderly population with high comorbidity burden)
- Evaluate for arrhythmias (atrial fibrillation — risk factor for mesenteric ischemia, a differential diagnosis)
- Assess for electrolyte-related changes (hypokalemia → U waves, prolonged QT; hypomagnesemia)
- Baseline cardiac assessment given high ASA class of this population [5]
15. Assessment
Gallstone ileus is a surgical emergency in elderly, comorbid patients. The classic presentation is an older woman with intermittent crampy abdominal pain, vomiting, and distension developing over days to weeks. The "tumbling" pattern of waxing-and-waning obstruction is characteristic but not always present.
- Most common impaction site: Terminal ileum (60–73%), due to its narrow caliber [5][10]
- Other sites: Jejunum (14%), duodenum (5% — Bouveret syndrome), colon (8%) [10]
- Most common fistula type: Cholecystoduodenal (68%) [10]
- Atypical presentations: Partial/intermittent obstruction, large bowel obstruction (cholecystocolonic fistula), post-cholecystectomy gallstone ileus [7]
- Complications: Bowel necrosis/perforation, AKI (30%), sepsis, recurrent gallstone ileus (<5%), gallbladder carcinoma (rare, associated with persistent fistula) [2][9]
16. Treatment Plan
Initial stabilization
- NPO, NGT decompression
- Aggressive IV fluid resuscitation and electrolyte correction (especially K⁺, Mg²⁺)
- Foley catheter for strict I/O monitoring
- Broad-spectrum antibiotics if septic or peritonitic
Surgical management (definitive treatment)
Key surgical pearls
- Enterolithotomy alone is the most commonly performed procedure (62%) and is associated with the lowest mortality on multivariate analysis (OR 2.86 for one-stage and OR 2.96 for bowel resection vs. enterolithotomy alone) [2]
- Always palpate the entire bowel for additional stones — occult second stones are found in up to 16% of cases [10][15]
- Recurrence rate after enterolithotomy alone is <5%, and only 10% require reoperation for biliary symptoms [3]
- For duodenal impaction, one-stage repair is favored since the fistula is in the same surgical field [9]
- For colonic impaction, one-stage repair is preferred due to risk of reflux cholangitis from fecal contamination [9]
- Laparoscopic-assisted enterolithotomy is feasible with comparable outcomes and potentially fewer major complications [16]
17. Disposition
- All patients require admission — gallstone ileus is a surgical condition requiring operative intervention [1][5]
- ICU admission: Hemodynamically unstable patients, significant comorbidities, post-operative monitoring in high-risk patients
- Surgical floor: Stable patients post-operatively
- Surgical consultation: Emergent general surgery consultation upon diagnosis — this is not a condition managed conservatively (rare exceptions: stones <2 cm may occasionally pass spontaneously) [13]
- GI consultation: Consider if Bouveret syndrome is suspected (potential for endoscopic lithotripsy) [6]
18. Follow Up / Return Precautions
- Post-discharge follow-up: General surgery within 1–2 weeks; consider interval cholecystectomy discussion at 4–6 weeks if enterolithotomy alone was performed
- Imaging follow-up: Consider abdominal ultrasound or CT at follow-up to assess for residual gallstones, fistula status, and gallbladder pathology
- Symptoms requiring immediate reassessment:
- Recurrent vomiting, abdominal pain, or distension (recurrent gallstone ileus — <5% risk) [3]
- Fever, jaundice, RUQ pain (cholangitis from persistent fistula)
- Wound infection signs (erythema, drainage, dehiscence)
- Patient counseling: Explain that if the gallbladder was left in situ, there is a small risk of recurrent gallstone ileus, cholangitis, and a theoretical long-term risk of gallbladder carcinoma associated with persistent cholecystoenteric fistula [9]
- Expected recovery: Median hospital stay is 7–10 days; full recovery over 4–6 weeks [16]
References
1. Gallstone Ileus: Case Report and Literature Review. — Dai XZ, Li GQ, Zhang F, Wang XH, Zhang CY. World Journal of Gastroenterology. 2013.
2. Surgery for Gallstone Ileus: A Nationwide Comparison of Trends and Outcomes. — Halabi WJ, Kang CY, Ketana N, et al. Annals of Surgery. 2014.
3. Gallstone Ileus: A Review of 1001 Reported Cases. — Reisner RM, Cohen JR. The American Surgeon. 1994.
4. Gallstone Ileus. — Molmenti EP. The New England Journal of Medicine. 1996.
5. Gallstone Ileus: Diagnosis and Management. — Ayantunde AA, Agrawal A. World Journal of Surgery. 2007.
6. Complications of Gallstone Disease: Mirizzi Syndrome, Cholecystocholedochal Fistula, and Gallstone Ileus. — Abou-Saif A, Al-Kawas FH. The American Journal of Gastroenterology. 2002.
7. Post-Cholecystectomy Gallstone Ileus. — Meier J, Guzzetta AA, Huerta S. The American Surgeon. 2020.
8. Gallstone Disease: Cholecystitis, Mirizzi Syndrome, Bouveret Syndrome, Gallstone Ileus. — Alemi F, Seiser N, Ayloo S. The Surgical Clinics of North America. 2019.
9. Gallstone Ileus: A Review. — Inukai K. BMJ Open Gastroenterology. 2019.
10. Gallstone Ileus. — Clavien PA, Richon J, Burgan S, Rohner A. The British Journal of Surgery. 1990.
11. The Role of Computed Tomography in Enterolith Causing Small Bowel Obstruction: A Case Series. — Zhang J, Xie P, Liu K. Medicine. 2023.
12. Gallstone Ileus Analysis of Radiological Findings in 27 Patients. — Lassandro F, Gagliardi N, Scuderi M, et al. European Journal of Radiology. 2004.
13. Value of CT in the Diagnosis and Management of Gallstone Ileus. — Yu CY, Lin CC, Shyu RY, et al. World Journal of Gastroenterology. 2005.
14. Comparative Analysis of MDCT and MRI in Diagnosing Chronic Gallstone Perforation and Ileus. — Liang X, Li W, Zhao B, Zhang L, Cheng Y. European Journal of Radiology. 2015.
15. Gallstone Ileus Displaying the Typical Rigler Triad and an Occult Second Ectopic Stone: A Case Report. — Wang L, Dong P, Zhang Y, Tian B. Medicine. 2017.
16. Laparoscopically Assisted or Open Enterolithotomy for Gallstone Ileus. — Moberg AC, Montgomery A. The British Journal of Surgery. 2007.