Black poop after constipation: what to know

Constipation commonly causes hard, dry stools and straining, but it does not by itself explain every black stool. Iron, bismuth remedies and dark foods may make stool look very dark. Black, shiny, sticky stool can reflect digested blood from higher in the digestive tract. Abdominal discomfort may also occur with [Constipation](/symptoms/constipation/), [Irritable Bowel Syndrome](/conditions/irritable-bowel-syndrome/) or [Diverticular Disease](/conditions/diverticular-disease/), but colour and texture still matter.

Look at the stool in good light and record its colour, texture, timing and any medicines or supplements. Sip fluids unless a clinician has restricted them, and avoid straining. Gradually improving fibre may help ordinary constipation, but do not rely on laxatives to manage unexplained black stool. A clinician can review medicines, examine you and decide whether tests are needed. Nutrition Counselling may help if diet is contributing.

Seek emergency care for black tarry stool with fainting, dizziness, severe weakness, vomiting blood, breathlessness or intense abdominal pain. Obtain same-day advice for repeated black stools, worsening pain, fever, or inability to pass stool and gas with vomiting. Signs such as a dry mouth, very little urine or confusion can indicate [Dehydration](/conditions/dehydration/) and need urgent attention.

Could my medicines or supplements account for the colour? Does the stool need testing for blood? What constipation plan is suitable, and could thyroid symptoms or [Hypothyroidism](/conditions/hypothyroidism/) be contributing?