Most women would kill for a size six figure and a gap between their thighs. But Amelia-Jane Harris, 20, says her new 'dream body' is actually a nightmare, as Crohn's disease means she is in constant pain and cannot eat. The illness has seen Miss Harris lose more than 18 stone (252lbs) in 20 months, as she regularly vomits up her food and suffers excruciating bowel pain. At her largest, when she weighed 27st 10lbs (388lbs) and was a size 32, she dreamed of pulling off skimpy outfits. But now, weighing just 8st 9lbs (121lbs) and wearing size 6 clothes, she says she would give anything to get back her fuller figure back and be able to eat normally again. Scroll down for video . Amelia-Jane Harris, 20, used to weigh 27st 10lbs and was bullied at school and called 'Fatty Bum Bum' (left). She developed Crohn's disease and lost 18 stone in 20 months to become a slim size six (right). But rather than being delighted at her new figure, she describes her situation as a 'nightmare' Her condition leaves her in constant pain and she can barely keep food down, so she can never enjoy eating or go out for dinner with her friends. She so tired from being malnourished she cannot work, and her fingernails, eyebrows and hair all regularly fall out. Miss Harris, of Chelmsley Wood, Birmingham, said: 'I get lots of compliments on my figure, but I have constant, underlying pain. 'Sometimes it feels like really severe stomach cramps, but I also get really bad stabbing pains that won't go away. 'I get no enjoyment out of food anymore. Eating feels like a chore because I know it's going to cause me pain. 'It seems pointless to make a healthy meal because I'll just throw it up. 'With strong painkillers I can cope, but it feels like a curse - I'm going to have to take this medication for the rest of my life.' Miss Harris was a happy and healthy child but her weight began to increase through her teens despite making no change to her diet. Miss Harris says her 'dream body' is actually a nightmare as she cannot eat and vomits daily . By the age of 14, she was dubbed 'Fatty Bum Bum' by playground bullies. She said: 'I ate whatever mum gave me, which was healthy because she was always watching her weight. 'As my waistline expanded, my confidence shrank and it wasn't until I left school - and the bullies - behind me that I stopped worrying about my size. 'At college, I ate what I wanted and although I reached nearly 28 stone, I still made an effort with my clothes, hair and make-up. Fat didn't have to mean ugly.' With the humiliation of her school days behind her, Miss Harris gradually started to embrace her size 32 frame. But then shortly after her 17th birthday, having finally made peace with being overweight, she fell seriously ill. She said: 'I started vomiting 10 times a day. I just couldn't keep anything down. 'Within 20 months I'd lost more than 18st. It didn't make any sense to me and I was terrified.' Concerned by the rapid and unprompted weight loss, she consulted her GP. In June 2014, after months of tests, her doctor diagnosed her with Crohn's disease, a long-term condition that causes inflammation of the lining of the digestive system. There is currently no cure for Crohn's disease - treatment simply aims to relieve the symptoms of the digestive system becoming inflamed. Miss Harris was immediately prescribed a cocktail of pills, which she is required to take every day. She said: 'On a good day I have to take up to 70 pills, but it can go up to 100 on a bad one. 'The weight kept falling off until I reached size six. People congratulated me on the weight loss and told me I looked fabulous – but the truth was I'd never felt worse' She now weighs 8st 9lbs, which means she is very slim for her 5tf 7in height. She said: 'I'll never be big again. I can only keep down around 10 per cent of what I eat, and right now I'm even struggling to keep down water.' Before the sickness started, Miss Harris would tuck into a healthy bowl of cereal for breakfast. Before being diagnosed with Crohn's disease, Miss Harris had four jobs. Now, she is so tired she cannot work. She said: 'I know it sounds unbelievable, but I'd give anything to be 27 stone again' For lunch she'd have a salad or a sandwich, and dinner was a meal cooked by her mother, such as a healthy portion of spaghetti bolognese made with reduced fat Quorn mince. Now, her condition means she cannot eat fats or oils. She has not eaten junk food for the past three years and has been on a strict diet of boiled meat and vegetables. She said: 'I know it sounds unbelievable, but I'd give anything to be 27 stone again. This time last year I held down four jobs, but now I'm too ill to work. 'Being curvy is part of what it means to be a girl. I had that before, but now I just look like a boy.' 'My fingernails have been known to drop off because I'm not getting any nutrients. 'I've also suffered really badly with hair loss. I wore a wig for the entire summer of 2013, which was hot, itchy and just generally uncomfortable. 'I even lost my eyebrows, which made me look like an alien. 'I can't go out and eat with my mates because I'll be sick. 'In the past when I've lost weight on purpose and people complimented me, I felt proud. Now, when people say "well done", I feel nothing.' Alarmingly, her weight is still decreasing and doctors are still baffled as to why her weight has not stabilised. She said: 'There's talk about admitting me back to hospital, but I'd give anything to avoid that. 'To some, I have the dream body - but to me, my size six figure is nothing but a nightmare. I can only pray that the doctors find the answer soon.' For more information and support, visit www.crohnsandcolitis.org.uk . Crohn's disease is a condition that causes inflammation of the digestive system . Crohn's disease is a condition that causes inflammation of the digestive system. Inflammation is the body's reaction to injury or irritation and can cause redness, swelling and pain. Crohn's causes ulcers to form in the gut and inflammation that affects the body's ability to digest food, absorb nutrients and eliminate waste in a healthy way. The disease is one of the two main forms of Inflammatory Bowel Disease (IBD).The other common form of IBD is Ulcerative Colitis. Crohn's is described as chronic, meaning it is a life-long condition. Sufferers will have periods of good health, remission, as well as times when their symptoms flare up or relapse. There is currently no cure for the disease, but drugs and surgery can give patients long periods of relief from their symptoms. The cause of Crohn's disease is not well understood. Experts believe the condition is, in part, inherited, while an abnormal reaction of the immune system to certain bacteria in the intestines is thought to contribute. Viruses, bacteria, diet, smoking and stress have all been suggested as environmental triggers, but there is no definitive evidence that any one of these is a cause of Crohn's. Symptoms include: . Abdominal pain and diarrhoeaTiredness and fatigueFeeling generally unwellMouth ulcersLoss of appetite and weight lossAnaemia - a reduced level of red blood cells . It's estimated around 250,000 people suffer from the condition in the UK. It can start in any age, but usually appears for the first time between the ages of 10 and 40. The disease can cause complications including perforations. They happen when a severe blockage ruptures the bowel, making a hole. The contents of the bowel can leak through and form an abscess. It causes pain and a fever. Source: Crohn's and Colitis UK .
Amelia-Jane Harris was 27st 10lbs at  17 and was called 'Fatty Bum Bum'
She began losing weight rapidly and was diagnosed with Crohn's disease .
Lost 18 stone in 20 months and became a slim size 6 weighing 8st 9lbs .
Says her dream body is a 'nightmare' as  is in constant pain and can't eat .