The color of 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:

1. DIARRHEA

In diarrhea, food travels through intestine fast, so intestinal bacteria don’t have time to convert bilirubin into stercobilin that gives stool it’s normal brown color. In other words, the stool in diarrhea from any cause may be yellow.

2. GERD

In people with gastro-esophageal reflux disease (GERD), food also travels through intestine fast and may therefore result in the yellow stool.

3. CHOLESTASIS

Cholestasis (Greek 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

The causes of cholestasis may be in the liver or outside the liver (listed below) (1).

3.1. LIVER DISEASE

When outflow of bile from the liver cells is impaired due to compressed small bile canals in the liver (intra-hepatic cholestasis), reduced amount of bile will appear in the intestine, and the stool will appear yellow/pale. Possible causes include:

  • Viral hepatitis
  • Alcoholic hepatitis
  • Cirrhosis
  • Cancer that has spread to the liver (liver metastases)
  • Tuberculosis
  • Lymphoma
  • Sjögren syndrome
  • Sarcoidosis
  • Amyloidosis

Common symptoms in liver disease are nausea, and tenderness/pain in 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, right below the ribs.

3.3. PANCREATIC DISEASE

The head of the enlarged pancreas may press on biliary duct and thus obstruct bile flow from the liver to intestine. This may occur in:

ABDOMINAL MASS

Abdominal tumor (like fibroma) may press on bile duct thus causing cholestasis, and yellow stools. Large tumors can be felt by hand, or they cause abdominal distension.

Further Reading:

Normal & Loose Bowel Movements
Find a Causes of Loose Bowel Movements From Medical Symptoms
Bowel Anatomy, Motility, Digestion & Gut Flora
Fructose Malabsorption
Green Bowel Movement
Black Bowel Movement
Mucus In Bowel Movement
Foods to Avoid in IBS

References:

  1. Cholestasis - causes and symptoms  (nlm.nih.gov/medlineplus)

Further Reading :
  • Gallbladder Removal Surgery – Cholecystectomy
  • Gallbladder Pain and Other Symptoms of Gallbladder Disease
  • Pale, Clay, Gray or White Bowel Movement & White Diarrhea
  • Orange Bowel Movement & Orange Diarrhea
  • Colon Cancer and Liver Disease