Discoloration, Feces

Black feces

Potential causes may include the following:^[1]

Digested blood
Medications: Acetazolamide, aluminum hydroxide, aminophylline, amphetamine, amphotericin, anticoagulants, aspirin, betamethasone, bismuth, charcoal, chloramphenicol, chlorpropamide, clindamycin, copper, cortisone, corticosteroid, cyclophosphamide, cytarabine, ethacrynic acid, ferrous salts, fluorides, fluorouracil, halothane, heparin, hydralazine, hydrocortisone, ibuprofen, indomethacin, levodopa, melphalan, methylprednisolone, methotrexate, nitrate, phenylephrine, phosphorous, potassium salt, prednisolone, procarbazine, salicylates, sulfonamide, tetracycline, thallium, theophylline, thiotepa, triamcinolone, warfarin

Blue feces

Causative medications may include boric acid, chloramphenicol, or methylene blue.

Clay feces

Causative diseases may include alcoholic hepatitis, biliary cirrhosis, gallstones, sclerosing cholangitis, biliary strictures, or viral hepatitis.^{[2, 3]}

Gray feces

Causative medications may include cocoa or colchicines.

Green feces

Potential causes may include the following:

Food: Spinach
Medications: Indomethacin, iron, medroxyprogesterone

Yellow feces

Potential causes may include the following:

Food: Rhubarb
Medication: Senna

Red feces

Potential causes may include the following:

Acute blood
Food: Blackberries
Medications: Aspirin, heparin, barium, lead, oxyphenbutazone, phenolphthalein, phenylbutazone, salicylate, senna, tetracycline syrup, hydroxocobalamin, rifampin^[4]