The color of the normal bowel movement is any shade of brown (usually medium brown), or brown/green. When stool appears apparently yellow/pale, and no relation to ingested food can be found, the following disorders should be considered:
In diarrhea, food travels through the intestine fast, so intestinal bacteria do not have time to convert bilirubin into stercobilin that gives stool its normal brown color. In other words, the stool in diarrhea from any cause may be yellow.
In people with gastro-esophageal reflux disease (GERD), food also travels through the intestine fast and may therefore result in the yellow stool.
Cholestasis (Gk. chole = bile, stasis= standing, meaning not flowing) is reduction or stoppage of bile flow from the liver into intestine. Lack of the bile in stool, makes stool light-colored. Undigested particles of the food may appear in the stool.
In cholestasis, bilirubin, and bile salts appear in the blood, skin and urine, resulting in
- Itchy skin
- Dark smelly urine
The causes of cholestasis may be in the liver or outside the liver (1):
3.1. LIVER DISEASE
When an outflow of the bile from the liver cells is impaired due to compressed small bile canals in the liver (intra-hepatic cholestasis), reduced amount of the bile will appear in the intestine, and the stool will appear yellow/pale. Causes include:
- Viral hepatitis
- Alcoholic hepatitis
- Cancer that has spread to the liver (liver metastases)
- Sjögren syndrome
Common symptoms in a liver disease are nausea and tenderness/pain in the upper right abdomen.
3.2. GALLBLADDER (BILIARY DUCT) DISEASE
When biliary duct, through which a bile flows from the liver into intestine is obstructed, less bile will appear in the stool, thus making stool yellow, pale, or even grey. Possible causes are:
- Gallstone from the gallbladder
- Tumor (cholangiocarcinoma)
- Inflammation (cholangitis)
Common symptom in gallbladder/biliary duct disease is cramping pain in upper right abdomen, below the ribs.
3.3. PANCREATIC DISEASE
The head of an enlarged pancreas may press on the biliary duct and thus obstruct bile flow from the liver to intestine. This may occur in:
- Pancreatitis (inflammation of the pancreas)
- Pancreatic cyst or cancer
An abdominal tumor (like fibroma) may press on the bile duct thus causing cholestasis and yellow stools. Large tumors can be felt by the hand, and may cause abdominal distension.
- Normal and Loose Bowel Movements
- Find a Causes of Loose Bowel Movements From Medical Symptoms
- Bowel Anatomy, Motility, Digestion and Gut Flora
- Fructose Malabsorption
- Green Bowel Movement
- Black Bowel Movement
- Mucus In Bowel Movement
- Foods to Avoid in IBS
- Cholestasis - causes and symptoms (nlm.nih.gov/medlineplus)