Fecal (Feculent) Vomiting
Fecal vomiting is most commonly caused by bowel obstruction, particularly distal small bowel or colonic obstruction, where intestinal contents back up and are eventually vomited.
Primary Mechanism
The condition occurs when intestinal obstruction prevents normal passage of bowel contents distally, causing retrograde movement and eventual vomiting of feculent material. In bowel obstruction, nausea and vomiting are earlier and more prominent in small bowel obstruction, though fecal vomiting specifically indicates more distal or prolonged obstruction 1.
Main Causes to Consider
1. Bowel Obstruction (Most Common)
Small bowel obstruction causes:
- Adhesions (55-75% of cases)
- Hernias (15-25%)
- Malignancies (5-10%) 1
Large bowel obstruction causes:
- Colorectal cancer (60% of cases)
- Volvulus (15-20%)
- Diverticular disease (10%) 1
Recent case reports confirm fecal vomiting as a presenting feature in colo-colic intussusception 2 and severe pyloric obstruction 3.
2. Gastrocolic or Gastrojejunocolic Fistula
An abnormal connection between the stomach and colon allows direct passage of colonic contents into the stomach. Classic presentation includes:
- Feculent eructation (foul belching)
- Fecal vomiting
- Diarrhea with undigested food (lienteric stools)
- Weight loss 4, 5
Barium enema demonstrates the fistula in 90-100% of cases 5. This typically occurs after peptic ulcer surgery complications or malignancy.
3. Severe Fecal Impaction
Massive fecal impaction, particularly in patients with neurologic disorders (Parkinson's disease, scleroderma), can cause complete functional obstruction leading to fecal vomiting 6.
Critical Clinical Approach
Look for these danger signs immediately:
- Peritoneal signs (suggests perforation or ischemia)
- Hemodynamic instability (tachycardia, hypotension, oliguria)
- Abdominal distension (positive likelihood ratio 16.8 for obstruction) 1
- Absent bowel sounds
- Examine ALL hernia sites and surgical scars
Laboratory red flags for ischemia:
- Elevated lactate
- Metabolic acidosis (low bicarbonate, low pH)
- Marked leukocytosis 1
Immediate Management Priority
Begin aggressive fluid resuscitation with isotonic crystalloids, nasogastric decompression, bowel rest, and obtain urgent imaging (CT abdomen/pelvis) while preparing for potential emergency surgery 1.
Common Pitfall
Do not delay imaging or surgical consultation waiting for "conservative management" to work if the patient has peritoneal signs, ischemia markers, or hemodynamic compromise—these indicate surgical emergencies requiring immediate intervention 1, 2.