If you’ve noticed what looks like two small holes near the top of your buttock crease, you’re most likely looking at pilonidal pits, small openings in the skin that form when loose hairs get pushed beneath the surface. These are extremely common, especially in people between 18 and 30, and they’re usually nothing dangerous. Less commonly, the holes could be a harmless anatomical feature you were born with or, in rarer cases, the openings of an abnormal tunnel called a fistula.
Pilonidal Pits: The Most Common Cause
A pilonidal sinus is a small channel or pocket that forms under the skin right at the top of the buttock crease, near the tailbone. On the surface, it shows up as one or more tiny holes or “pits” that can look like enlarged pores. Having two of them is completely typical. The word “pilonidal” literally means “nest of hair,” and that’s essentially what’s happening beneath the skin: loose hairs have punctured inward, and your body has formed a small pocket around them trying to push them back out.
Friction, pressure, tight clothing, cycling, and long periods of sitting all increase the likelihood of this happening. During World War II, the condition was nicknamed “Jeep driver’s disease” because it was so common among soldiers who sat in vehicles all day. Today, truck drivers and office workers face the same risk. The condition is roughly twice as common in men as in women, with peak rates around age 20 in men and 18 in women.
When a pilonidal sinus isn’t infected, you might not have any symptoms at all. The pits just sit there. Problems start when the pocket beneath the skin fills with hair, debris, and bacteria, forming a cyst or abscess. At that point you’ll notice swelling, redness, warmth, pain when sitting, and possibly pus or blood draining from the openings. Some people also develop a low fever. An infected pilonidal cyst can be intensely painful and typically needs medical treatment to drain and heal.
Coccygeal Pits: A Normal Variant
Not every small hole near the tailbone is a pilonidal sinus. A coccygeal pit is a shallow dimple located right at the very bottom of the buttock crease, directly over the tip of the coccyx (tailbone). It’s a normal anatomical variation that some people are born with. According to clinical guidelines from Johns Hopkins, a coccygeal pit has no connection to the spinal canal and doesn’t require any imaging or medical evaluation. It’s simply how your skin formed during development.
The key difference is location. A coccygeal pit sits below the level of the buttock crease, while a pilonidal sinus typically forms within or just above the crease. A coccygeal pit also tends to be shallow enough that you can see the bottom of it, and it won’t produce discharge or become painful on its own. If you have two small, painless dimples that have been there as long as you can remember and have never caused symptoms, there’s a good chance they fall into this category.
Anal Fistula: A Less Likely Possibility
If the holes you’re noticing are closer to the anus rather than up near the tailbone, an anal fistula is worth considering. A fistula is an abnormal tunnel that develops between the inside of the anal canal and the outer skin around the anus. It usually forms after an anal abscess (a painful collection of pus) that has drained or burst. The external opening can look like a small hole that persistently oozes pus, blood, or stool. It’s typically accompanied by pain, swelling, and irritation that doesn’t fully go away.
Anal fistulas are distinct from pilonidal pits in both location and symptoms. They sit lower on the body, much closer to the anal opening, and they almost always cause ongoing discharge and discomfort. They don’t resolve on their own and generally require a surgical procedure to close the tunnel.
How To Tell What You’re Dealing With
Location is the single biggest clue. Two small pits near the top of the crease between your buttocks, close to the tailbone, point toward pilonidal disease or a normal coccygeal variant. Holes closer to the anus suggest a fistula. Symptoms matter too: if the area is painless and has never drained anything, you’re likely looking at something benign. If there’s swelling, pain when sitting, or any kind of discharge, a pilonidal infection or fistula is more likely.
A doctor can usually diagnose pilonidal pits just by looking at them. No special imaging is needed in most cases. They’ll check how many pits are present, whether there’s any sign of a deeper pocket or abscess, and whether the area shows signs of infection.
Treatment for Pilonidal Pits
If your pilonidal pits aren’t causing symptoms, treatment isn’t always necessary. Keeping the area clean, removing hair regularly (through shaving or laser hair removal), and avoiding prolonged sitting can prevent flare-ups.
When infection does develop, the initial treatment is usually draining the abscess, which provides fast pain relief. For recurring problems, a minimally invasive procedure called pit picking has shown strong results. A study of adolescent patients found that 92% were symptom-free and recurrence-free an average of five months after the procedure. Patients needed only over-the-counter pain relief for up to three days and returned to normal activities almost immediately. Larger studies tracking patients over longer periods have reported recurrence rates between 6% and 16% over five to ten years, which compares favorably to more invasive surgical options that require longer recovery times.
For people with complex or repeatedly recurring disease, more extensive procedures that remove the entire sinus tract may be recommended. Recovery from these takes longer, sometimes several weeks, but they offer a more definitive solution for stubborn cases.
Why It’s Getting More Common
Pilonidal disease appears to be increasing. A Danish population study tracking cases from 1996 to 2021 found that the incidence rose from about 26 to 40 cases per 100,000 people per year over that period. The median age at first diagnosis has also shifted slightly younger. Researchers suspect that more sedentary lifestyles and tighter-fitting clothing may be contributing factors, though the exact reasons for the trend aren’t fully settled.