A stoma is surgically formed to divert the normal flow of faeces (colostomy and ileostomy) or urine (urostomy or ileal conduit) into a stoma appliance. A concern of patients following the formation of their stoma is what they can eat and drink. Unfortunately, there is limited evidence (Mitchell et al, 2020) to guide this advice, most of which is anecdotal. It is important to consider the reason that the stoma was formed, as well as the type of stoma formation when considering diet.
When stomas are formed for cancer, for example, there may be pre-operative weight loss or in an emergency there may be cachexia. Weight loss may also occur pre-operatively for people with inflammatory bowel disease, due to the frequent toileting when their disease was in flair. For people with Crohn's disease, there might be long-term issues with absorption of nutrients, whereas for people with diverticular disease there might be the need to address constipation.
In the initial postoperative period advice for all people with a stoma is often to eat small, frequent meals that are well chewed. This helps to prevent issues such as postoperative weight loss.
In general, the three different stomas have slightly different dietary issues that need to be considered.
Urostomy
A urostomy is formed with a piece of small bowel so, in the initial postoperative period, there can be disruption to bowel function. This is not usually a long-term issue but fluid intake can be. It is important for people with a urostomy to drink around 1500-2000 ml of fluid each day (Black, 2000). This will help to keep the urine clear. Urine will have a small amount of mucus in it, produced from the bowel used to form the stoma. There is limited evidence that intake of cranberry juice can reduce the volume of mucus passed (Temiz and Cavdar, 2018). Increasing amounts of mucus in the urine can indicate a urinary infection that needs urgent attention because this infection will relate to the kidneys and not the bladder, which has been removed.
Colostomy
A colostomy is formed from the colon and the faeces are usually soft and formed. However, for people who were prone to irritable bowel syndrome-type symptoms, such as constipation or loose stool in the pre-operative period, this may still occur. Constipation can be addressed by changing dietary intake to include more fibre such as that contained in fruit and vegetables. It is important to also consider the fluids that are drunk, aiming for about 1500 ml daily (Black, 2000). Constipation can also be prevented by movement such as a 20-minute walk each day, which also has other health benefits.
Ileostomy
People with an ileostomy potentially face different issues. The ileostomy is formed from the small bowel and thus the large bowel is unable to undertake its role of additional salt and fluid reabsorption. The small bowel undertakes most of the absorption of nutrients and fluids, but the waste that leaves the ileostomy will be loose faeces.
‘A concern of patients following the formation of their stoma is what they can eat and drink. Unfortunately there is limited evidence to guide advice, most of which is anecdotal’
The faecal output is usually described as having a porridge-like consistency and requires the ileostomy appliance (stoma bag) to be emptied about four to six times each day. The loose faeces also contain more fluid and salts than those that were previously passed from the anus. This fluid and salt need to be carefully replaced. However, if too much fluid is taken orally, it has the potential to increase fluid loss rather than replace it, which sounds counterintuitive.
It is advisable for people with an ileostomy to drink about 1500-2000 ml of fluid each day (Black, 2000). In addition, about a teaspoon of salt should be added daily to food to replace the salt lost in the ileostomy output. The small bowel also has a smaller diameter than the large bowel, so there is a risk of it becoming blocked; therefore careful chewing of food is needed. Constipation is not something that can occur for people with an ileostomy but a food bolus blockage is a risk. Foods that are hard to digest are more likely to cause problems. Foods that are commonly reported to be problematic are sweetcorn, popcorn and tough meat.
It is a misconception that fruit and vegetables cannot be eaten by people with an ileostomy. However, it is common practice to omit them from the diet for a few weeks after surgery and then gradually reintroduce them. This is because of the oedema that occurs during the surgical formation of a stoma. The swelling reduces the diameter of the small bowel and increases the risk of a blockage.
A blockage can present with symptoms such as abdominal discomfort, nausea and a reduced output from the ileostomy. Also, in the postoperative period the faeces can be loose. Dietary manipulation can help to ‘thicken’ the faeces. This can be achieved by replacing wholemeal with white versions of carbohydrates such as bread and pasta.
It is advisable for people with an ileostomy to have a low-fibre diet to prevent loose stool. When fruit and vegetables are reintroduced into the diet it is advisable to not eat raw versions initially, except bananas, which are an exception that can be encouraged soon after surgery. Well-cooked vegetables and tinned versions are better tolerated initially. It is important to avoid excluding food groups from the diet and, if other dietary needs exist, such as diabetes or vegetarian diets, it can be useful to have a dietetic consultation.
In general, after about 8 weeks following surgery, the postoperative swelling will have subsided and more variation in the diet can be achieved with less risk of a blockage. Exclusion diets should be avoided and general healthy diets can be followed by most people with a stoma. Supplements are rarely needed but people with a persistent loose faecal output from their ileostomy should be considered for additional support, which may include an anti-diarrhoea medication such as loperamide or oral electrolyte supplements.
A balanced diet
For people with a faecal output stoma, food particles, such as tomato skins, may be visible in the faeces. The colour of the faeces or urine might change with excessive consumption of certain foods such as beetroot. However, any blood in the faeces needs to be urgently reviewed.
Nurses need to encourage a balanced diet for all people with a stoma. That said, some changes may be needed from the diet that was taken before the stoma formation, especially for people with an ileostomy. If dietary changes do not address the needs of the patient, nurses should consider referral to a dietitian or stoma nurse.