A relative of mine had this done and she was just 7.5 stone.
She had very very bad reflux so they needed to bypass the stomach and basically did a roux en y.
Is that what you're having? She was part of a cohort of very early surgery involving nissenfundoplications.
Anyway, she was much thinner than you and 5ft 9.
Life wasn't always easy after but if she hadn't had it, she would have died from aspiration into the lungs and malnutrition. She could hardly eat towards the end.
So it was life-saving. She did put on weight but things were a struggle.
Long-term the side effects were post bariatic hypoglaecemia. Rare, but not that rare it seems. Dumping is also a possibility.
Some slight issues with the pancreas, she took Creon with some success.
The thing to mention is that your ability to absorb vitamins may well be compromised.
I'm sure this will be covered but get tested regularly, it could literally save your life. I do feel she went downhill due to lack of nutrients being absorbed over a decade or two. So I hope you'll stay ontop of your vitamins if you can. I know it's very hard but you've got this. Good luck.
From the NHS:
Vitamin and Mineral Supplements after Gastric Bypass or Sleeve Gastrectomy
After your surgery
Multivitamin and Mineral supplements are mandatory for life after you have had a gastric bypass or sleeve gastrectomy.
Some multivitamins and minerals can be prescribed by your GP. Alternatively you can purchase some over the counter from pharmacies and supermarkets.
After surgery the quantity that you will be able to eat reduces and this combined with changes to your stomach and small intestine (that result in some mild malabsorption), will mean that you may not absorb sufficient vitamins and minerals. Daily vitamin and mineral supplements are essential to reduce the risk of any deficiencies and keep you well.
You will need the following:
A complete A-Z multivitamin and mineral formula – daily
Begin to take your multivitamin and mineral as soon as possible after surgery. You will be given a soluble formula (for 1 month) when you are discharged from hospital. After this your GP can prescribe you with tablets. Take your supplement with or after food to reduce the risk of side effects such as nausea.
Calcium and Vitamin D (combined) formula – 1200-1500mg/daily from food and supplements
Calcium is an essential mineral for your bone health, cell and muscle function, and is better absorbed with the presence of vitamin D.
Taking calcium and iron together can interfere with the others absorption, so take these supplements at separate times across the day, leaving at least a 2 hour gap between them.
An iron supplement – daily for women of menstrual age (or if you have anaemia)
Iron is essential for the formation of red blood cells that carry oxygen around the body. Iron deficiency can cause anaemia and symptoms include; fatigue, palpitations, pale skin, hair loss and a sore mouth.
Taking iron and calcium together can interfere with the others absorption, so take these supplements at separate times across the day, leaving at least a 2 hour gap between them.
A separate Vitamin D3 (in addition to calcium/Vitamin D combined supplement) – 20,000IU once each week (or 2,000-4,000IU daily)
Vitamin D helps regulate the amount of calcium and phosphate in the body. It helps to keep bones, teeth and muscles healthy. In adults Vitamin D deficiency can lead to bone pain caused by a condition called Osteomalacia in adults.
B12 (Hydroxycobalamin) 1mg intramuscular injection - every 3 months
Vitamin B12 is involved in helping the body make red blood cells and keeps the nervous system healthy. The changes to your stomach and small intestine after bariatric surgery can affect your absorption of B12.
Deficiency may result in fatigue, weakness, a sore, red tongue or mouth ulcers. More serious consequences of deficiency include; pins and needles, disturbed vision, depression, confusion, and problems with memory.
Take all of your vitamins and mineral every day but do not take them all together. Spread them evenly across the day to help your body absorb them.
Here is an example: