Clinical safety
Use your own team’s instructions first
Use the contact number and urgent-care advice your team gave you for new or worsening symptoms. If you are having systemic anti-cancer treatment, use the 24-hour number on your treatment alert card. Call 999 for a life-threatening emergency.
Start with your normal pattern and the treatment context
“Normal” varies. A change matters because of its frequency, duration, associated symptoms, treatment and effect on hydration and function.
A bowel record the team can use
Keep it brief and include the details that can change advice.
- Your usual bowel pattern and what has changed in frequency, consistency, urgency or control.
- When the change began in relation to treatment, surgery, medicines, diet or infection exposure.
- Pain, swelling, vomiting, blood, fever, inability to pass wind or other associated changes.
- What you can drink and eat, urine changes and whether you feel dizzy or weak.
- Any stoma and the output instructions supplied by the stoma team.
- Laxatives, anti-diarrhoeal medicines or other products already prescribed and exactly how they were used.
- The contact threshold given by your treatment team, especially during immunotherapy.
Before changing what you take
Ask which cause the team is considering and which option is safe for you.
- Could treatment, infection, obstruction, medicines or a late effect explain this change?
- Should any test or examination happen before using another remedy?
- What food and fluid approach fits my treatment and other health conditions?
- Which prescribed medicine should be adjusted, and only by whom?
- When should I call again if the first plan does not work?
If you are receiving immunotherapy
Name it even if the bowel change seems manageable.
“I am receiving a checkpoint inhibitor and have a new bowel change with abdominal pain. I know this can need prompt assessment, so I am calling before taking anything new.”
Describe the bowel change precisely and act on red flags
Cancer, surgery, medicines, infection, reduced intake and treatment can all alter the bowel. Because management for diarrhoea, constipation and obstruction can conflict, identify the pattern before reaching for a familiar remedy.
For diarrhoea, record the number of stools compared with normal, whether they are watery, urgent, nocturnal, bloody or accompanied by pain, fever or dizziness. Immunotherapy-related bowel inflammation can begin with apparently ordinary diarrhoea and needs early oncology review. Do not self-treat with an anti-diarrhoeal medicine when the treatment team has told you to call first, or when blood, severe pain, fever or suspected infection is present.
Constipation can involve hard stool, reduced frequency, straining or a sense of incomplete emptying. Opioid pain relief, anti-sickness medicine, dehydration, low intake, immobility and bowel narrowing can contribute. Ask for a preventive bowel plan when starting constipating medicines. Do not simply add fibre or strong laxatives if there is vomiting, marked swelling, severe cramping or inability to pass wind, because obstruction needs assessment.
Hydration and diet advice must reflect stomas, kidney or heart disease, diabetes, swallowing and the location of surgery or radiotherapy. Bring a short bowel record to the clinician rather than making repeated major food changes. A sample may be requested if infection is possible. Skin protection around the anus or stoma also matters when frequent output causes soreness.
A practical way through it
Use the parts that fit your situation and leave the rest.
- Define the change from normalRecord frequency, consistency, urgency, blood or mucus, pain, wind, vomiting, temperature and when the last comfortable bowel movement occurred.
- Link it to recent careNote treatment dates, surgery, antibiotics, opioid pain relief, anti-sickness drugs, laxatives, tube feeds and any sick contacts or unusual food exposure.
- Use the cancer team's triggerCall at the frequency or symptom threshold it supplied, especially during immunotherapy, transplant care or treatment likely to lower immunity.
- Protect fluid balance safelyUse the individual fluid and salt advice from the team and report dizziness, thirst, reduced urine or inability to drink rather than relying only on stool count.
- Check before self-treatmentAsk before starting or increasing anti-diarrhoeals, laxatives, enemas, suppositories, fibre products or supplements when cancer treatment or bowel surgery is involved.
- Care for sore skinUse gentle cleaning, pat dry and apply only a barrier recommended for the affected area, seeking nursing advice before skin becomes broken.
What this can look like
When constipation might be obstruction
Ravi has taken opioid pain relief and not opened the bowels for three days. Now there is cramping, a swollen abdomen, vomiting and no wind.
A useful response
Contact the urgent cancer or surgical service immediately and describe all four features.
Do not take extra fibre, an enema or repeated laxative doses unless a clinician advises it after assessment.
Call 999 if pain is severe with collapse, breathing difficulty or rapidly worsening illness.
Possible causes
- A bowel diary can record frequency, consistency, pain, blood, medicines and food.
- New symptoms after treatment should not automatically be dismissed as a late effect.
Safe management
- Follow personalised fluid and diet advice, especially with a stoma or fluid restriction.
- Ask before starting anti-diarrhoeal medicine, laxatives or major fibre changes.
Urgent warning signs
- Call for persistent symptoms, blood, fever or dehydration.
- Severe pain, swelling or vomiting with no stool or wind may indicate obstruction.
A manageable next step
What you could do now
- Start a simple bowel and medicine diary.
- Check any over-the-counter treatment with your team.
- Use the 24-hour number for severe or rapidly worsening symptoms.
Checked sources
Read the original guidance
We summarise carefully and link to the source so you can check the full, most current information. Sources were checked 9 September 2026.