Medicines, absorption and the colour of your output

One rule governs the rest: you should not stop taking any prescribed tablets or medicines without consulting your doctor. Any drug may have some effect on output and colour.

Forms that may not be absorbed

• Enteric coated — not absorbed in the stomach. Prednisolone, iron tablets, potassium and salt tablets may be excreted whole before proper absorption has taken place.
• Modified release, or slow release — some angina medicines and cold remedies may be difficult to absorb.
• The contraceptive pill, which is a case of its own: oral contraceptives may not be fully effective, as they may not be absorbed completely.

Drugs that change output

Diuretics — water tablets — get their own warning: these should be used with caution as they may cause dehydration and deplete your body salts.

The colour chart

• Iron — black
• Charcoal — black
• Antibiotics — green
• Anticoagulants — red
• Aspirin — red

Not everything red is blood

The colour chart is worth reading next to the food one, because between them they explain most alarming moments. Beetroot, tomato and red wine can all make output appear blood-stained, and output after eating beetroot is easily mistaken for bleeding. Anticoagulants and aspirin can do the same thing. That is not a reason to ignore bleeding — persistent bleeding is a reason to contact your doctor or stoma care nurse — but it is a reason to check what you ate before you panic.

The medicines to pause when you are ill

There is one situation where the general rule about never stopping a prescribed medicine has a published exception, and it is worth knowing about in advance rather than discovering mid-illness. The national Medicine Sick Day Guidance says that during an illness that could cause dehydration — including high stoma or pouch output — certain medicines should be suspended temporarily.

• ACE inhibitors, ending in “-pril” — blood pressure
• angiotensin receptor blockers, ending in “-sartan” — blood pressure
• NSAIDs such as ibuprofen, diclofenac and naproxen — painkillers
• metformin — diabetes
• SGLT2 inhibitors, ending in “-flozin”
• diuretics such as furosemide, bendroflumethiazide and spironolactone

These must be RESTARTED when you are well again — usually 24 to 48 hours, once the illness settles, output normalises and you are eating and drinking. And although the rules are nationally adopted: if you have concerns about stopping your medication, speak to your GP, NHS 111 (NHS 24 in Scotland), your stoma nurse or your local pharmacy.

One more absorption problem belongs here. Fast transit through the gut during high output means medications may not be absorbed adequately — so a drug that stops working during a bad week is not necessarily a drug that has stopped working.