This week's dilemma: Can a 13-year-old have bulimia? I always thought it was for older woman who were unhappy and lonely, but I saw my daughter make herself sick after eating an ordinary meal. She denied it, but I know what I saw. She is quite thin, though she has a healthy appetite. I think she is popular.

However, her teachers told me at the last parents' night that she isn't working as hard. What do you think?

Readers' replies
Be careful not to jump to conclusions. You might be misinterpreting what you saw; she might have vomited from something she ate, and that what's all this could be about.

I would urge you to trust your daughter. She has told you there is nothing wrong, so you ought to believe her unless you know for sure that she is lying.

LI, by e-mail.

I am in my late twenties and I've had bulimia for more than a decade. With help from my doctors, I am better at controlling the impulses which make me want to punish and hurt myself by becoming thin. I honestly believe I could have avoided all this pain if my parents had recognised the problem when I was a teenager. This illness needs to be treated as soon as it appears - that didn't happen with me, and I am still paying the price.

BV, by e-mail.

As a medical professional who specialises in working with adolescents with serious eating disorders, I can assure you that girls even younger than your daughter turn up at my clinic with bulimia. Having said that, I think you are probably over-reacting here. That one incident where you saw your child throwing up doesn't mean anything on its own. The only time to get worried is if you notice other symptoms, like she is eating secretly or has long discussions about how she thinks she is too fat when in fact she is thin.

AP, by e-mail.

She sounds like a healthy teenager to me. There is nothing wrong in wanting to have a good figure, and there are plenty of normal 13-year-olds who don't work as hard as they could in school. You are taking a very extreme view of your daughter's mental condition on the basis of that one-off occurrence (which she denies anyway). The media talk about bulimia and anorexia constantly, so no wonder that idea is in your head. Calm down and give your daughter your trust.

MK, by e-mail.

The parent doctor's reply
Statistics show that while the onset of bulimia typically occurs during the late teenage years, it is becoming increasingly common in younger children - so yes, a 13-year-old certainly can have bulimia. The condition is characterised by consuming huge amounts of food very quickly, then self-induced vomiting very soon after.

Bulimia affects females more than males, and evidence from research suggests that around 4% of women experience bulimia at some stage in their lives. Other than deliberate vomiting, bulimics may try to get rid of the food they eat by taking laxatives, pills or excessive physical exercise. Tell-tale signs of bingeing include lots of food wrappers lying around (although they may be concealed). There may be some form of self-harm as well. Fortunately, there are various forms of professional treatment.

Regarding your 13-year-old, I tend to agree with LI and MK who both suggest you should be cautious about diagnosing her with this problem. Your worry is understandable, but a single instance of vomiting - which your daughter claims was not self-induced - is not enough to support a conclusion that she has bulimia. Rather than confronting your teenager at this stage, I suggest you monitor her closely over the next few months. Subtly keep an eye on her eating habits and watch out for disappearances into the bathroom immediately after meals. You could also occasionally check her room for food wrappings. In addition, make sure you have a good dialogue with her about her progress in school. Explain that her teachers feel she isn't working hard enough, and try to resolve any school-based problems she is experiencing.

I am sure you'll find that your fears of bulimia are unfounded. Yet if your concern does persist, and if this is based on hard evidence, seek professional advice, starting with your GP.