Stool Changes

Stool varies far more than most people expect, and diet accounts for the majority of day-to-day change. Colour responds to what you eat and take: beetroot and red food colouring can mimic blood, iron tablets and bismuth turn stool black, and antibiotics loosen it. Consistency tracks fibre and fluid intake, activity, and transit time - the Bristol stool scale is the useful shorthand, with types 3 and 4 representing comfortable normality. Frequency is normal anywhere from three times a day to three times a week; what matters is a change from your own pattern. The changes that carry weight are persistence and company. Pale, putty-coloured stool with dark urine suggests a bile duct problem; black tarry stool suggests upper gastrointestinal bleeding; and fresh red blood, while often haemorrhoidal, should never be assumed to be so, particularly after age 45. A persistent change in bowel habit lasting more than 3 weeks, especially with weight loss or anaemia, is a recognised red flag for colorectal cancer screening. Supplements play a limited and specific role: soluble fibre such as psyllium at 5-10 g/day normalises both loose and hard stool, and strain-specific probiotics have modest evidence in antibiotic-associated diarrhoea.