The reality star, 31, who is currently pregnant with her second child, welcomed her her first baby with husband Hugo Taylor in May 2020.
In a lengthy post on Instagram, she said they were helped by a postnatal doula for the first three weeks, but added: “I didn’t leave the house for at least a week when I felt strong enough to go for a walk around the block.
“I slowly started increasing the length of my walks but got carried away I did too much and ended up in bed with cramps and with heavy bleeding.
“My advice is to listen to your body and take it very slowly, get as much help as you can so that you can rest and let your body heal.”
Discussing the realities of her recovery, Mackintosh said: “I spent the first few days wearing adult nappy pants (which I highly recommend) then moved on to big cotton knickers with an industrial sized pad, and slowly reduced this down to a panty liner.”
She said she had a dressing applied directly to her wound and had to inject herself in the thigh for around 10 days to reduce the chance of a blood clot.
Mackintosh continued: “I see photos of other new mums who walk out of hospital on the same day and are off to the park post smiling selfies with their families and newborn and think its amazing, but my reality was very different.
“I felt fragile, exhausted, emotional, self conscious and in a state of shock for the first few weeks and it took me months to feel physically strong again.
“After six weeks I saw my obstetrician and a women’s physio and was given the all clear to start exercising again, I started with Pilates and introduced light weight training from about eight weeks and slowly built (my) strength back up.”
Last month, Mackintosh revealed she is expecting a second daughter, announcing the news in a gender reveal video soundtracked by Girls Just Want To Have Fun by Cyndi Lauper.
She said she is planning on having another caesarean when she gives birth to her second child.
Mackintosh and Taylor tied the knot in 2018. The reality star was previously married to musician Professor Green.